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Medial Patellofemoral Ligament Reconstruction Combined With Distal Realignment for Recurrent Dislocations of the Patella: 5-Year Results of a Randomized Controlled Trial

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Background: Tibial tubercle transfer (TTT) and medial patellofemoral ligament (MPFL) reconstruction have both shown, either in isolation or in combination, to provide improved patellofemoral joint (PFJ) stability. There are few studies that provide evidence that this remains true in the long term. Purpose: To compare the long-term results of patellar instability after TTT with and without MPFL reconstruction in 2 randomized groups. Study design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 34 patients (36 knees) were randomized to 2 groups. The first group underwent lateral release (LR) and TTT for confirmed maltracking of the patella (control group). The second group underwent MPFL reconstruction in addition to TTT and LR (reconstruction group). Patients were followed up with validated questionnaires (Kujala score, Tegner activity score), a visual analog scale (VAS) assessing their insecurity, and a clinical assessment at a minimum of 5 years postoperatively. Participants also underwent quantitative computed tomography (CT) at 1 year for comparison. Two patients in the control group and 1 patient in the reconstruction group were lost to follow-up at 5 years. Results: There were no significant differences in the Kujala ( P = .75), Tegner ( P = .36), or VAS ( P = .75) scores at any time period. One patient in the control group sustained a patellar redislocation at 3 years. Five patients in the control group and 2 in the reconstruction group had functional failures and required reoperations; however, this was not statistically significant ( P = .30). There were no significant differences between groups in the time to return to school or work ( P = .65) or sports ( P = .38) after surgery. Overall patient satisfaction was higher in the reconstruction group compared with the control group ( P = .04), and quantitative CT scans showed that the reconstruction group had a statistically significant improvement in the mean patellar tilt (6° vs -8°, respectively; P = .03) and mean congruence angle (13° vs -11°, respectively; P = .03) in the quadriceps-contracted state compared with the control group. Conclusion: Reconstruction of the MPFL in addition to TTT and LR resulted in improved alignment parameters (congruence angle, patellar tilt angle) as well as patient satisfaction. The Kujala and Tegner scores were no different between the 2 groups at any time period. There was insufficient evidence to conclude that the addition of MPFL reconstruction to TTT results in fewer redislocations or reoperations. This study concludes that MPFL reconstruction improves PFJ alignment and patient satisfaction; however, further studies with larger patient numbers are required to satisfy its significance with respect to redislocation rates and functional scores in the long term.
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Medial Patellofemoral Ligament
Reconstruction Combined With Distal
Realignment for Recurrent Dislocations
of the Patella
5-Year Results of a Randomized Controlled Trial
Iswadi Damasena,
*
y
MBBS, Murray Blythe,
z
FRACS(Orth), David Wysocki,
y§
FRACS(Orth),
David Kelly,
||
MBBS, and Peter Annear,
§
FRACS(Orth)
Investigation performed at the Perth Orthopaedic & Sports Medicine Centre, Perth, Australia
Background: Tibial tubercle transfer (TTT) and medial patellofemoral ligament (MPFL) reconstruction have both shown, either in
isolation or in combination, to provide improved patellofemoral joint (PFJ) stability. There are few studies that provide evidence
that this remains true in the long term.
Purpose: To compare the long-term results of patellar instability after TTT with and without MPFL reconstruction in 2 randomized
groups.
Study Design: Randomized controlled trial; Level of evidence, 1.
Methods: A total of 34 patients (36 knees) were randomized to 2 groups. The first group underwent lateral release (LR) and TTT
for confirmed maltracking of the patella (control group). The second group underwent MPFL reconstruction in addition to TTT and
LR (reconstruction group). Patients were followed up with validated questionnaires (Kujala score, Tegner activity score), a visual
analog scale (VAS) assessing their insecurity, and a clinical assessment at a minimum of 5 years postoperatively. Participants also
underwent quantitative computed tomography (CT) at 1 year for comparison. Two patients in the control group and 1 patient in
the reconstruction group were lost to follow-up at 5 years.
Results: There were no significant differences in the Kujala (P= .75), Tegner (P= .36), or VAS (P= .75) scores at any time period.
One patient in the control group sustained a patellar redislocation at 3 years. Five patients in the control group and 2 in the recon-
struction group had functional failures and required reoperations; however, this was not statistically significant (P= .30). There
were no significant differences between groups in the time to return to school or work (P= .65) or sports (P= .38) after surgery.
Overall patient satisfaction was higher in the reconstruction group compared with the control group (P= .04), and quantitative CT
scans showed that the reconstruction group had a statistically significant improvement in the mean patellar tilt (6°vs 28°, respec-
tively; P= .03) and mean congruence angle (13°vs 211°, respectively; P= .03) in the quadriceps-contracted state compared with
the control group.
Conclusion: Reconstruction of the MPFL in addition to TTT and LR resulted in improved alignment parameters (congruence
angle, patellar tilt angle) as well as patient satisfaction. The Kujala and Tegner scores were no different between the 2 groups
at any time period. There was insufficient evidence to conclude that the addition of MPFL reconstruction to TTT results in fewer
redislocations or reoperations. This study concludes that MPFL reconstruction improves PFJ alignment and patient satisfaction;
however, further studies with larger patient numbers are required to satisfy its significance with respect to redislocation rates and
functional scores in the long term.
Keywords: patellofemoral instability; recurrent patellar dislocation; MPFL reconstruction; tibial tubercle transfer
The nonoperative management of patellofemoral instabil-
ity has been reported to have long-term recurrence rates
of up to 49%.
16,17
Half of those who do not suffer a further
dislocation fail to return to their chosen sport by 6
months.
1
The condition is known to be multifactorial,
with malalignment, patellofemoral dysplasia, patella alta,
soft tissue imbalance, and ligamentous laxity contributing
variably in individual cases. Operations to address these
factors can be grouped into proximal soft tissue balancing,
The American Journal of Sports Medicine, Vol. XX, No. X
DOI: 10.1177/0363546516666352
Ó2016 The Author(s)
1
distal bony procedures, and trochleoplasty. The modified
Elmslie-Trillat procedure consisting of medial rotation tib-
ial tubercle transfer (TTT) combined with lateral release
(LR) addresses both soft tissue and bony abnormalities.
28
Case series have generally reported satisfactory outcomes,
13
although long-term recurrence rates of up to 13% have been
reported.
5,18
Autograft reconstruction of the medial patellofemoral
ligament (MPFL) has become an increasingly common pro-
cedure in the last decade. Three systematic reviews
reported satisfactory functional outcomes and low redislo-
cation rates but noted that available evidence consists
mainly of case series of varying techniques and participants
of differing age ranges.
3,15,24
Two randomized controlled tri-
als (RCTs) have compared isolated MPFL repair to nonoper-
ative management in first-time dislocators and reported
conflicting outcomes for redislocation rates and functional
outcomes.
2,6
There has been no RCT of MPFL reconstruc-
tion compared with other surgical treatments.
This study investigated the additional benefit of MPFL
reconstruction for patients undergoing TTT and LR for
recurrent patellar instability. Our primary hypothesis
was that MPFL reconstruction would improve subjective
outcome measures. Additionally, we aimed to examine
the effect of MPFL reconstruction on postoperative redislo-
cations, functional failures, patient satisfaction, and post-
operative patellar kinematics based on dynamic
computed tomography (CT).
METHODS
Design
We designed a prospective RCT. Eighty-seven knees in 84
consecutively referred patients with recurrent lateral
patellar dislocations were assessed for enrollment in the
study between December 2007 and November 2010.
Approval was obtained from a hospital ethics committee,
and all participants gave informed consent. Patients were
not informed of their allocation until the conclusion of
the study.
The inclusion criteria were (1) 3 lateral patellar dislo-
cations, (2) no congenital or habitual dislocations, (3)
abnormal patellar tracking as determined by the presence
of ‘‘J’’ tracking and lateral subluxation of the patella
through a qualitative assessment of CT scans, (4) skeletal
maturity, (5) no previous patellofemoral realignment pro-
cedure (bony or soft tissue), (6) no significant ligamentous
knee injury, (7) absent or minor patellofemoral joint (PFJ)
degenerative arthropathy, and (8) competence to consent
to the trial and follow-up period.
A total of 39 patients (39 knees) were excluded (Figure
1): 15 had undergone previous realignment surgery, 8
had fewer than 3 dislocations, 6 were skeletally immature,
4 had other significant ligamentous knee injuries, 4 had
moderate to severe degenerative PFJ arthropathy, 1 did
not have subluxation on CT, and 1 was a habitual disloca-
tor. Eleven patients (12 knees) declined involvement in the
study. Thirty-six knees in 34 consecutive patients with
recurrent lateral patellar dislocations were randomized to
undergo TTT and LR (control group) or TTT, LR, and
MPFL reconstruction (reconstruction group). Patients
were randomized to each group by computer-generated
instructions placed into sealed, opaque envelopes. The
envelopes were then opened in the operating theater once
general anesthesia had been administered.
Seventeen patients (18 knees) were randomized to the
control group, and all underwent TTT and LR as allo-
cated. Two patients (2 knees) were lost to follow-up. One
patient was not able to be contacted by any means at all
follow-up intervals. One patient declined to attend fol-
low-up visits after the 3-month follow-up and before post-
operative CT because of an interstate move. The
remaining 16 knees were observed at a minimum of 5
years postoperatively.
*
Address correspondence to Iswadi Damasena, MBBS, Orthopaedic Surgery Department, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands,
Perth 6008151, Western Australia (email: iswadi.damasena@health.wa.gov.au).
y
Orthopaedic Surgery Department, Sir Charles Gairdner Hospital, Perth, Australia.
z
Southern Cross Orthopaedic Group, Perth, Australia.
§
Perth Orthopaedic & Sports Medicine Centre, Perth, Australia.
||
Orthopaedic Surgery Department, Royal Perth Hospital, Perth, Australia.
One or more of the authors has declared the following potential conflict of interest or source of funding: P.A. has received institutional support from
Corin Australia Pty Ltd and Smith & Nephew Australia.
Assessed for eligibility
(84 patients/87 knees)
Randomized
(34 patients/36 knees)
Excluded (50 patients/
51 knees)
• 39 did not meet inclusion
criteria
• 11 declined participation
Control group:
TTT + LR
(17 patients/18 knees)
Reconstruction group:
TTT + LR + MPFL
(17 patients/18 knees)
15 patients (16 knees);
2 lost to follow-up
• 1 unable to be reached
• 1 declined
16 patients (17 knees);
1 lost to follow-up
• 1 unable to be reached
15 patients (16 knees) 16 patients (17 knees)
Enrollment
Allocation
Follow-up
1 year
Follow-up
5+ years
Figure 1. Patient flowchart. LR, lateral release; MPFL,
medial patellofemoral ligament; TTT, tibial tubercle transfer.
2Damasena et al The American Journal of Sports Medicine
Seventeen patients (18 knees) were randomized to the
reconstruction group, and all underwent TTT, LR, and
MPFL reconstruction as allocated. One patient could not be
contacted at any follow-up interval. The remaining 17 knees
were observed at a minimum of 5 years postoperatively.
Sample Size
Based on a comparison of 2 independent groups, a sample
size of 16 participants per group was estimated to have suf-
ficient power (b= 0.2) to detect a difference of 7 points in
the Kujala score. This difference was based on the Kujala
scores in a case series of modified Elmslie-Trillat proce-
dures published in the literature
13
compared with an
unpublished case series from this center of a modified Elm-
slie-Trillat procedure combined with MPFL reconstruction.
Assuming a 10% rate of a loss to follow-up, a sample size of
18 in each group was recruited.
Surgical Technique
All procedures were performed by the senior author (P.A.).
An arthroscopic assessment of the knee was performed and
additional pathological conditions addressed as required. If
present, patellofemoral chondropathy was assessed for
severity by the Outerbridge classification and the pattern
according to Pidoriano et al.
19
LR was performed arthroscopically using radiofre-
quency ablation (VAPR; DePuy Mitek). This was per-
formed in the inferolateral retinaculum in all patients to
prevent tethering of the extensor mechanism with TTT.
When there was less than 1 quadrant of medial patellar
glide, the release was extended to the level of the proximal
pole of the patella. TTT was then performed through
a 5-cm transverse incision centered over the middle third
of the tibial tuberosity extending medially to the pes anser-
inus using longitudinal osteotomy oriented for anteromedi-
alization. The osteotomy site was translated approximately
8 to 10 mm and temporarily held with a drill bit. Tracking
through a range of motion was reassessed arthroscopically.
Normal tracking was defined as patellar central engage-
ment on the trochlea 40°of knee flexion viewed through
an anterolateral portal. The osteotomy procedure was
adjusted if required. When confirmed appropriate, the
tubercle was fixed with 2 fully threaded cancellous AO
4.0-mm screws (DePuy Synthes).
In the reconstruction group, the graft was harvested
before TTT. The semitendinosus tendon was harvested
using a custom tendon stripper, leaving the pes anserinus
insertion preserved. The free end was whipstitched by
4cmwithNo.1Vicryl(EthiconInc)suturetoallowgraft
passage and tensioning. Through a 3-cm transverse medial
patellar incision, a medial-to-anterolateral bone tunnel was
created at the midpoint of the patella using a 4.5-mm drill
bit. The graft was passed subcutaneously from the first inci-
sion to the second, through the bone tunnel from anterolat-
eral to medial, and then deep to the medial retinaculum to
a tunnel based 3 mm proximal to the medial epicondyle.
The graft was not fixed within the patellar tunnel. The
femoral tunnel was reamed to 7 mm over a guide wire
directed 30°proximally and anteriorly exiting the lateral
femoral cortex to allow free tensioning of the graft. The graft
was initially tensioned in extension with the patella manu-
ally reduced to the center of the trochlea and then adjusted
to allow 1 patellar quadrant of lateral glide. Tracking was
arthroscopically reassessed through a range of motion,
with the patella confirmed to be engaging the trochlea at
\40°of knee flexion. If there was medial tilt or translation
in terminal extension or excessive tension in deep flexion,
then the graft tension was adjusted. When confirmed appro-
priate, the knee was placed in full extension and the graft
secured with a 7-mm interference screw (Guardsman;
Conmed Linvatec) in the tunnel at the medial epicondyle.
Rehabilitation was identical for both groups. Active flex-
ion exercises began on the first day postoperatively.
Patients were fully weightbearing immediately but wore
an extension splint when ambulating for the first 3 weeks.
Return to sport was permitted when the rehabilitation
goals had been achieved.
Clinical Evaluation
Patients were assessed preoperatively; at 6 weeks, 3
months, and 12 months; and at a minimum of 5 years at
final follow-up. The clinical assessment at the 6-week
follow-up was performed by the senior author (P.A.). The
assessments at all other time periods were performed by 3
authors (I.D., M.B., D.W.) who were independent of the sur-
gical procedures and patient care. The assessors could not
be blinded, as the pattern of incisions indicates whether
MPFL reconstruction had been performed. At each time
period, patients were assessed for passive knee extension,
active knee flexion, apprehension, tenderness over the
osteotomy and hamstring donor sites, dislocations, return
to work or school, and return to sports in addition to self-
administered scores consisting of the Kujala patellofemoral
functional score,
12
the Tegner activity level score,
26
apatient
satisfaction score, and an ‘‘insecurity’’ visual analog scale
(VAS) score. For the VAS, the patients made a mark on
a 100-mm line indicating how insecure they perceived their
patella to be, as described by Watanabe et al
29
(from ‘‘com-
pletely secure’’ at 0 mm to ‘‘dislocating’’ at 100 mm). Patient
satisfaction was assessed on a 5-point Likert-type scale,
with participants asked to rate the outcome of their surgery
as excellent (1), good (2), fair (3), poor (4), and worse (5). Pri-
mary outcomes were measured as the redislocation rate and
functional failures requiring reoperations. Secondary out-
comes were measured as the Kujala score, Tegner score,
and VAS score.
Radiological Evaluation
Patients underwent quantitative patellofemoral CT preop-
eratively and postoperatively between the 3- and 12-month
follow-ups. CT was performed in a standardized manner.
The patellar height measurement was adapted from a tech-
nique described for magnetic resonance imaging (MRI)
21
to
AJSM Vol. XX, No. X, XXXX MPFL Reconstruction and Distal Realignment for Patellar Dislocations 3
allow all measurements to be performed from the same
investigations.
Statistical Analysis
The Kujala scores for both groups were compared at all
postoperative time periods after adjusting for baseline var-
iables using analysis of covariance (repeated-measures
analysis of covariance [ANCOVA]). These comparisons
were repeated for the Tegner activity score; VAS score;
range of motion data; and change in patellar tilt, patellar
height, congruency angle, and trochlear dysplasia based
on CT findings. The necessary assumptions for the analy-
sis were assessed and deemed appropriate for the data.
The association between group and categorical data was
evaluated by means of a Pearson chi-square test or Fisher
exact test depending on which was most suitable. Subjec-
tive patient satisfaction (Likert-type scales with 2 groups)
was analyzed using a Wilcoxon rank-sum test. A 2-sided P
value of \.05 indicated statistical significance.
RESULTS
Patients
The groups were comparable for sex, age, side, age of first
dislocation, other knee injuries, and previous operations
(Table 1). One patient in the control group had a nonopera-
tively managed posterior cruciate ligament injury 3 years
after her initial patellar dislocation. She had a stable pos-
terior drawer test result before her procedure. All previous
operations on the ipsilateral knee consisted of arthroscopic
removal of loose bodies or osteochondral fragments and
debridement. All patients had a positive preoperative
patellar apprehension test result. The groups were compa-
rable for patellofemoral and other intra-articular patholog-
ical conditions (Table 2).
Functional Scores
The Tegner, Kujala, and VAS scores for each time period
are presented in Figures 2, 3, and 4, respectively. The
ANCOVA indicated no significant differences between
the groups for any of the scores. At the 6-week follow-up,
there was a trend for the reconstruction group to have
a lower insecurity VAS score (mean 6SD, 13 68.5 mm)
compared with the control group (27 619.8 mm), although
this was not statistically significant (P= .07). At 5 years,
functional scores were maintained or improved in compar-
ison to those at the 12-month follow-up, although there
was no statistical significance between the 2 groups (P=
.75 [Kujala] and .36 [Tegner]).
TABLE 1
Demographic and Knee Characteristics
Control
Group
(n = 16)
Reconstruction
Group
(n = 17)
Sex, male/female, n 5/11 3/14
Age, y, mean (range) 16 (14-29) 21 (12-47)
Age of first dislocation, y,
mean (range)
16 (12-19) 17 (7-29)
Other ipsilateral knee injuries, n 1 0
Other ipsilateral knee operations, n 4 4
TABLE 2
Arthroscopic Intraoperative Findings
at the Time of Reconstruction
Control
Group
(n = 16)
Reconstruction
Group
(n = 17)
Patellar chondropathy, n 11 9
Outerbridge grade, mean (range) 2.1 (1-3) 2.3 (1-3)
Chondropathy pattern, mean (range)
a
2.6 (1-4) 2.8 (1-4)
Other intra-articular injuries, n 3 2
a
According to Kujala et al.
12
0
1
2
3
4
5
6
7
8
9
10
Tegner Score
TTT MPFL
6 weeks 3 months 12 months 5+ years
Preoperative
Figure 2. Tegner activity score. MPFL, medial patellofemoral
ligament; TTT, tibial tubercle transfer.
40
50
60
70
80
90
100
110
TTT MPFL
Preoperative
Kujala Score
6 weeks 3 months 12 months 5+ years
Figure 3. Kujala score. MPFL, medial patellofemoral liga-
ment; TTT, tibial tubercle transfer.
4Damasena et al The American Journal of Sports Medicine
Clinical Evaluation
At final follow-up, 5 of 16 patients in the control group and
2 of 17 in the reconstruction group were found to have
a ‘‘functional failure’’ (ie, a positive apprehension test
result, a history of subluxation episodes after surgery, or
a PFJ dislocation). There was no statistical difference
between the 2 groups (P= .30). Patient satisfaction scores
(Figure 5) were higher in the reconstruction group, 88%
(15/17) excellent compared with 56% (9/16) in the control
group, and this was statistically significant (P= .04).
Patients returned to work or school at a mean of 1.5 6
2.6 months in the control group and 1.2 60.7 months in
the reconstruction group (P= .65). Three (19%) in the con-
trol group and 6 (35%) in the reconstruction group did not
return to sport by the 1-year follow-up, but this was not
statistically significant (P= .43). At 5 years, all patients
had returned to a sporting activity; however, the majority
of them (90%) had not returned to their preinjury level of
sport. Of the patients who did return to sport, this occurred
at a mean of 3.8 63.2 months in the control group and 3.0
61.8 months in the reconstruction group (P= .38).
There were no significant differences in range of motion
preoperatively or postoperatively at any follow-up period
(Table 3). At the 6-week follow-up, there was a trend
toward greater flexion in the control group than the recon-
struction group, with a mean of 136.5°613.4°compared
with 120.4°620.5°, respectively (P= .07).
Radiological Evaluation
The quantitative CT findings are shown in Table 4. The
preoperative CT scans showed that the 2 groups had a sim-
ilar but wide variation of tibial tubercle (TT) lateralization,
the congruence angle, and the patellar tilt. There was no
difference in the patellar height (tendon length/patellar
length) between the 2 groups preoperatively (P= .26) or
postoperatively (P= .13). Trochlear dysplasia was
assessed on preoperative CT, and patients were deemed
to have a shallow dysplastic trochlea if they had a troch-
lear angle (TA) of .145°or a trochlear sulcus depth
(TD) of \3 mm. Both groups were comparable (Table 5),
and no statistically significant difference was found
between the 2 groups for the TA (P= .90) or TD (P=
.06). Postoperative assessments showed a similar magni-
tude of TT medialization between the groups. For the
patellar tilt, there was more (worsened) tilt postopera-
tively in the control group by a mean of 1°in the quadri-
ceps-relaxed state and 8°in the contracted state. The
reconstruction group showed a mean 5°and 6°less tilt
in the relaxed and contracted states, respectively. The
change in patellar tilt between the groups was not signif-
icant in the relaxed state (P= .16) but was significant in
the contracted state (P= .03).
For the congruence angle, there was more subluxation
postoperatively in the control group, with a mean 1°
increase in the quadriceps-relaxed state and 11°in the con-
tracted state. The reconstruction group showed a mean 11°
and 13°less subluxation in the relaxed and contracted
states, respectively. The change in congruence angle
between the groups was not significant in the relaxed state
(P= .24) but was significant in the contracted state (P=
.03). Typical postoperative lateral radiographs are dis-
played in Figure 6.
Complications
One patient in the control group sustained a patellar disloca-
tion 3 years after surgery while playing sports; the reconstruc-
tion group had no dislocations. There were 7 other
complications in the control group: 2 superficial wound infec-
tions, 1 patient requiring removal of TT screws, 2 patients
with TT screw irritation but not requiring removal, 1 pares-
thesia of the infrapatellar branch of the saphenous nerve,
TTT MPFL
10
20
30
40
50
60
70
80
0
6 weeks 3 months 12 months 5+ years
Preoperative
VAS Score
Figure 4. Visual analog scale (VAS) score for insecurity.
MPFL, medial patellofemoral ligament; TTT, tibial tubercle
transfer.
0
2
4
6
8
10
12
14
16
Excellent Good
Fair Poor Worse
TTT MPFL
Patient Satisfaction
(No. of Patients)
Figure 5. Subjective patient satisfaction at 5 years. MPFL,
medial patellofemoral ligament; TTT, tibial tubercle transfer.
TABLE 3
Range of Motion for Both Groups at Each Time Period
a
Control Group Reconstruction Group
Extension,
deg
Flexion,
deg
Extension,
deg
Flexion,
deg
Preoperatively 2.8 65.9 142.8 67.3 4.1 64.6 145.1 68.5
6 weeks –0.4 61.3 136.5 613.4 –0.8 62.7 120.4 620.5
3 months 1.6 64.6 142.8 69.3 3.0 64.0 136.3 69.7
1 year 1.7 64.3 141.7 66.2 3.1 64.6 141.4 611.5
5 years 1.5 64.2 141.9 66.3 2.3 63.6 142.1 67.6
a
Data are reported as mean 6SD.
AJSM Vol. XX, No. X, XXXX MPFL Reconstruction and Distal Realignment for Patellar Dislocations 5
and 1 postoperative vasospasm that resolved spontaneously.
There were 2 complications in the reconstruction group: 1
deep infection requiring arthroscopic lavage and 1 patient
requiring removal of TT screws. The patient with a deep infec-
tion was included in the analyses at all follow-ups.
DISCUSSION
The challenge facing surgeons in managing patients with
recurrent patellar dislocations has been well documented.
Decision making is multifactorial, and clear guidelines
for optimal treatment are yet to be determined. MPFL
reconstruction has proved popular in the past decade,
with patients undergoing the procedure having improved
functional results and low redislocation rates.
2,3,6,14,15,23,24
Most long-term studies however are case series, use varying
methods for reconstructing the MPFL, and often combine
them with other procedures, both bony and soft tissue.
Reported results often have no comparison group, leaving
surgeons with the difficult choice between several treatment
options. To our knowledge, this is the first RCT to add
MPFL reconstruction to another surgical procedure.
Both the control and reconstruction groups showed
improved functional scores at a minimum 5-year follow-
up. Tegner activity, Kujala, VAS, and patient satisfaction
scores improved for both groups. The clinically significant
change in the VAS score for patellar insecurity is unknown,
but Crossley et al
7
reported that the minimum clinically
important change in the VAS score for patellofemoral pain
for both patients and clinicians is 20 of 100 mm. Other
measures of rehabilitation progress such as time to return
to work or school and return to sports were not different.
CT demonstrated an improvement in both the congruence
angle and patellar tilt in the reconstruction group but not in
the control group. This was statistically significant in the
quadriceps-contracted state but not in the relaxed state.
The MPFL graft was tensioned intraoperatively, such that
there was at least 1 quadrant of lateral glide possible pas-
sively. Therefore, the effect of MPFL reconstruction would
only be expected in the contracted state, as was found.
Although the difference in the functional scores was not sta-
tistically significant between the 2 groups, the reconstruction
group had better patient satisfaction, fewer episodes of insta-
bility or ‘‘functional failures,’’ and fewer reoperations. It
remains to be seen if these findings reflect improved patello-
femoral maltracking and hence contact pressures within the
PFJ, thereby reducing long-term chondral wear and eventual
osteoarthritis. Further long-term results will be required to
better answer this question.
The reconstruction group showed a trend toward less
flexion and lower functional scores at 6 weeks, which was
TABLE 5
Preoperative Computed Tomography Results
of Trochlear Dysplasia
a
Control
Group
Reconstruction
Group
P
Value
Trochlear angle, deg 143.6 68.4 143.8 67.7 .90
Trochlear sulcus depth, mm 5.1 61.6 6.2 61.6 .06
a
Data are reported as mean 6SD.
Figure 6. Postoperative lateral radiographs for the (A) con-
trol and (B) reconstruction groups.
TABLE 4
Preoperative and Postoperative Quantitative Computed Tomography Results
a
Preoperative Postoperative
Control Group
(n = 16)
Reconstruction Group
(n = 17)
Control Group
(n = 15)
Reconstruction Group
(n = 16)
Trochlear angle, deg 143 68.6 144 67.9
TT-TG distance, mm 16 63.2 15 63.5 10 65.0 12 64.3
Congruence angle, deg
Relaxed 24 617.0 17 618.3 25 618.0 6 619.5
Contracted 38 623.1 41 622.6 49 615.3 29 622.1
Patellar tilt angle, deg
Relaxed 0 611.7 6 67.9 –1 69.9 10 68.8
Contracted –5 614.8 –2 612.8 –12 610.2 3 614.1
TL/PL (patella alta), mm 1.40 60.15 1.34 60.15 1.44 60.22 1.33 60.18
a
Data are reported as mean 6SD. PL, patellar length; TL, tendon length; TT-TG, tibial tubercle–trochlear groove.
6Damasena et al The American Journal of Sports Medicine
not found at further follow-up. This may reflect greater pain
due to the additional procedure, which was not specifically
quantified. Another explanation could be excessive con-
straint in deep flexion caused by a nonanatomic MPFL posi-
tion. In this study, the femoral tunnel was positioned at the
medial epicondyle. We have since modified our technique by
using image intensification to more accurately replicate the
anatomic origin proximal and posterior to the medial
epicondyle.
20
That there was little change in the control group’s radio-
graphic alignment is surprising. The measured TT medial-
ization, which does not measure anteriorization, was small
but similar between the groups and so unlikely to explain
the difference in postoperative alignment. All postopera-
tive and most preoperative CT scans were assessed by
the same radiologist. When the patient presented to the
clinic with CT already performed at another facility, it
was thought impractical to repeat the scans; as such, there
may have been an interobserver error, although this would
not be expected to be selective.
The redislocation rates and functional scores reported
for isolated MPFL reconstruction have generally been
excellent. The mean postoperative Kujala scores in 2
recent systematic reviews ranged from 83 to 96.
3,24
How-
ever, it was noted that there was significant heterogeneity
in the inclusion criteria for the studies and the surgical
technique. One of the reviews included first-time patellar
dislocators together with redislocators.
15
Some studies
did not exclude patients if they had undergone previous
knee surgery or if they were habitual dislocators, for exam-
ple.
24
Furthermore, most of the reported studies were only
of a short-term follow-up, making a direct comparison
between our results and these difficult.
There are a number of weaknesses in our study. First,
the assessors were not blinded to the treatment. The addi-
tional incisions required for MPFL reconstruction made it
impossible to blind the assessors, leading to a risk of mea-
surement bias. Patients themselves were not informed of
which arm of the study they were in; however, it must
again be deduced that this may be assumed from the sur-
gical scars. Similarly, although the radiologist assessing
the CT scans was not informed of patient allocation, this
can be determined from the images.
The study did not have a group of patients that underwent
MPFL reconstruction alone. Unfortunately, at the time of
recruitment, this was not the standard practice of the leading
surgeon, the decision to perform TTT being based on an
assessment of maltracking, not the TT–trochlear groove
(TT-TG) distance. Isolated MPFL reconstruction is generally
accepted for TT-TG distances \20 mm, above which TTT is
recommended.
8
The mean preoperative TT-TG distance for
the control and reconstruction groups was 16 mm and
15 mm, respectively. It could be argued that these patients
only required MPFL reconstruction. A recent study by
Stephen et al
25
questioned this distance and found that
patellar tracking and contact pressures can be restored to
normal by isolated MPFL reconstruction up to a TT-TG dis-
tance of 15 mm, whereas those patients with TT-TG distan-
ces in excess of this may benefit from an additional TT
medialization procedure. Camp et al
4
also noted that the
TT-TG distance was not an accurate predictor of patellar
instability and devised a more patient-specific method that
takes patient size and individualized bony anatomy into
account. Thaunat and Erasmus
27
went a step further and sug-
gested that their failed MPFL reconstructions were caused by
unaddressed bony pathological abnormalities, including
abnormal TT-TG distances.
Although both groups were comparable for CT meas-
ures of trochlear dysplasia, the accuracy of this may be
questioned. Some authors have previously reported diffi-
culty in measuring the trochlear sulcus angle at 0°of flex-
ion, as was done in this study.
9,11,21
The interobserver and
intraobserver reliability of this measure was much better
at 20°of flexion. Ideally, trochlear dysplasia would have
been measured at 20°of flexion on preoperative radio-
graphs (classified by Dejour) or MRI; however, this was
not possible in our study.
There has been a trend toward quantitative radiology-
directed realignment protocols to tailor operations to indi-
vidual patients.
10
This is in contrast with the standardized
surgical technique used in this study after selection by
clinical and qualitative CT assessments. The former
approach may help identify subcategories of patellofemoral
instability, particularly the severity of dysplasia, in which
the addition of MPFL reconstruction is beneficial or is
appropriate alone. Achieving sufficiently powered studies
of such subgroups will be difficult.
Sillanpaa et al
22
were the first to report on the long-
term results of MPFL reconstruction compared with distal
realignment for recurrent patellar dislocations. In their
retrospective case series, 47 Finnish military servicemen
were reviewed at a mean follow-up time of 10.2 years.
Eighteen underwent adductor magnus tenodesis and 29
a Roux-Goldthwait procedure for distal realignment. These
authors noted that 5 patients demonstrated patellofemoral
osteoarthritis in the Roux-Goldthwait group and none in
the adductor magnus tenodesis group. They concluded
that MPFL reconstruction reduces the risk of osteoarthri-
tis compared with distal realignment surgery. Although
this study was not randomized, used only male partici-
pants, and did not include preoperative results, their find-
ings suggest that MPFL reconstruction may improve
patellofemoral kinematics and hence reduce chondral
wear. There is not enough evidence in the literature how-
ever to comment on isolated MPFL reconstruction in
patients with documented TT-TG distances .15 mm. In
these patients, larger contact pressures in the PFJ result
from greater tension in the MPFL graft.
25
As a result,
the increased joint reaction forces and elevated articular
contact pressures may predispose to early chondral wear
in the PFJ. We therefore recommend realignment proce-
dures be considered in these patients in addition to
MPFL reconstruction to reduce wear patterns and poten-
tially patellofemoral osteoarthritis.
CONCLUSION
Reconstruction of the MPFL in addition to TTT and LR
resulted in improved alignment parameters (congruence
AJSM Vol. XX, No. X, XXXX MPFL Reconstruction and Distal Realignment for Patellar Dislocations 7
angle, patellar tilt angle) as well as patient satisfaction.
The Kujala and Tegner activity scores were no different
between the 2 groups at any time period. There was insuf-
ficient evidence to conclude that the addition of MPFL
reconstruction to TTT results in fewer redislocations or
reoperations. This study concludes that MPFL reconstruc-
tion improves PFJ alignment and patient satisfaction;
however, further studies with larger patient numbers are
required to satisfy its significance with respect to redisloca-
tion rates and functional scores in the long term.
ACKNOWLEDGMENT
The authors thank David Hille for providing support with
statistical analysis.
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8Damasena et al The American Journal of Sports Medicine
... Medial patellofemoral ligament (MPFL) reconstruction is a commonly performed surgery for recurrent patella dislocation. 4,12 The ultimate goal of this surgical procedure is to restore the primary medial soft tissue restraint to resist laterally directed forces on the patella, thereby preventing lateral dislocation of the patella. Establishing appropriate graft tension in MPFL reconstruction has proven to be difficult. ...
... Establishing appropriate graft tension in MPFL reconstruction has proven to be difficult. [1][2][3][4][5] Proper surgical technique should adequately restore the medial restraint to resist lateral subluxation of the patella and prevent recurrent patellar dislocation while avoiding overconstraint of the patellofemoral joint (PFJ) and increasing patellofemoral contact pressures. [1][2][3][4][5] The challenge is compounded by the lack of a reliable and reproducible method to tension the MPFL graft. ...
... [1][2][3][4][5] Proper surgical technique should adequately restore the medial restraint to resist lateral subluxation of the patella and prevent recurrent patellar dislocation while avoiding overconstraint of the patellofemoral joint (PFJ) and increasing patellofemoral contact pressures. [1][2][3][4][5] The challenge is compounded by the lack of a reliable and reproducible method to tension the MPFL graft. Biomechanical studies have demonstrated a force of 2 N during MPFL reconstruction can restore contact pressures and lateral restraint to a near anatomic state. ...
Article
Full-text available
Background When performing a medial patellofemoral ligament (MPFL) reconstruction, surgeons may place the MPFL graft under higher than anatomic tension to minimize the chance of recurrent instability. Purpose To investigate whether a lateral retinacular release (LRR) significantly decreases patellofemoral contact pressures after an overtensioned (OT) MPFL reconstruction. Study Design Controlled laboratory study. Methods Mean and peak pressure across the patellofemoral joint at 30°, 45°, and 60° of flexion was assessed in 14 cadaveric knee specimens with intact MPFL, transected MPFL, reconstructed MPFL with graft OT, and OT MPFL with LRR. The Wilcoxon signed rank test was used to determine differences across states, with W and C values calculated when possible. Results Mean pressure decreased significantly after MPFL transection compared with intact at 30° (456.9 ± 116.8 vs 410.9 ± 109.4 N, P = .006, W < 7) and 45° (404.9 ± 91.7 vs 369.4 ± 85.3 N, P = .005, W < 5) and increased significantly from intact to OT graft at 30° (456.9 ± 116.8 vs 563.0 ± 11.2 N, P = .003, W < 7), 45° (404.9 ± 91.7 vs 481.4 ± 14.8 N, P = .005, W < 5), and 60° (272.9 ± 139.0 vs 367.0 ± 53.7 N, P = .007, W < 3). Peak pressure increased significantly between intact and OT graft at 30° (1364.0 ± 478.2 vs 2094.4 ± 619.8 N, P = .002, W < 9), 45° (1224.7 ± 491.5 vs 1676.7 ± 779.1 N, P = .005, W < 5), and 60° (1117.7 ± 566.8 vs 1604.2 ± 772.9 N, W < 3). In knees with significantly increased mean pressure after overtensioning, mean pressure increased by 23.3% (11/14 knees) at 30°, 18.3% (10/14 knees) at 45°, and 35.0% (10/14 knees) at 60°. Peak pressure increased significantly by 35.3% (30°), 25.2% (45°), and 29.3% (60°). A significant decrease in mean pressure, toward but not to baseline, was observed between the OT and LRR states at 30° (563.0 ± 11.2 vs 501.5 ± 9.3 N, W < 7) and 60° (367.0 ± 53.7 vs 302.0 ± 13.8 N, W < 5) and a decrease in peak pressure at 30° (2094.4 ± 619.8 vs 1886.5 ± 655.3 N; W < 9). Conclusion LRR led to a statistically significant decrease in pressure across the patellofemoral joint in knees that demonstrated increased contact pressures after an OT MPFL graft. Clinical Relevance LRR after an MPFL reconstruction in which the MPFL graft has been OT may help reduce patellofemoral contact pressures at the time of surgery.
... [8] Reconstruction of this ligament is an important and well-established soft tissue patella stabilizing procedure. [1,2,[9][10][11][12][13][14] In children, allograft MPFL reconstruction can preserve native tissue and can be advantageous for patients with ligamentous laxity and connective tissue disorders. There are only limited numbers of studies reviewing the use of allograft in hypermobile children for MPFL reconstruction with small numbers. ...
Article
Introduction: Medial patellofemoral ligament (MPFL) reconstruction is used to treat patellofemoral instability either in isolation or in combination with other procedures. Use of allograft can preserve native tissue in children and can be advantageous in patients with connective tissue disorders, including ligamentous laxity. There is limited evidence regarding functional outcomes of allograft MPFL reconstruction in children and adolescents. This study aimed to assess the short to mid-term results of allograft MPFL reconstruction in children with hypermobility at a tertiary pediatric orthopedic center. Materials and methods: We retrospectively reviewed all children and adolescents who had undergone allograft MPFL reconstruction over 4 years. The primary outcome measure was the validated Kujala score for patellofemoral disorders. The secondary outcome measures included complications such as redislocation of the patella needing revision surgery. Patients with hypermobility were quantified using Beighton criteria. Statistical analysis was performed using Graph Pad Prism (V6). Results: Between 2012 and 2016, the senior author performed 76 allograft MPFL reconstructions in 57 patients. Nineteen patients had bilateral surgery. The mean age was 14 (7-16) years with a female: male ratio of 3:1. The mean Beighton score was 7. Hypermobility was part of a syndrome in ten patients. The mean follow-up was 3 (1-4) years. Nine patients had trochleoplasty and six patients had tibial tubercle osteotomy, in addition to allograft MPFL reconstruction. These fifteen patients, who had additional procedures, were excluded during the analysis of the outcome measures. The mean Kujala score was 89 (80-100). The overall complication rate was 11% (9/76). These included two patella fractures and seven (9%) patients with recurrent instability needing revision surgery. There was no significant difference in complication rates between syndromic and nonsyndromic patients (P = 0.9). Conclusion: Our study shows excellent short to mid-term functional outcomes of allograft MPFL reconstruction in children and adolescents with hypermobility.
... 34 Distal realignments combined with MPFL reconstruction allow for increased improvement in alignment parameters, in particular, the patellar tilt and congruence angles. 35 This recent combination of techniques has allowed for highly successful outcomes in many patients, especially patients who are skeletally immature. Although MPFL reconstruction has proved to be a leading procedure for patellar instability, with the help of other procedures (Fig. 6), such as the Roux-Goldthwait or Grammont distal realignment and lateral retinacular release, surgeries can be even more successful for targeted patients (Box 1). ...
Article
Through this article, the authors aim to summarize the techniques performed on both first time and recurrent skeletally immature patients experiencing patellar dislocation. This article focuses on several key points, such as the importance of medial patellofemoral ligament femoral insertions being distal to the growth plate and performing extensive lateral release and quadricep tendon lengthening in cases of obligatory dislocation. Although acknowledging the procedures discussed cannot be considered for all patients, as individuals with open growth plates may require additional operative time, in many cases these techniques yield high rates of success.
... 6 The combination strategies of these surgical methods were frequently proposed over the past years. 6,14,25,26 Du et al 6 conducted a prospective study showing MPFL reconstruction in association with LPR release is a best combination surgical strategy in terms of postoperative patellar stability and knee joint function. Zhao et al 27 demonstrated MPFL reconstruction is more effective than MPR plication in combination surgeries including LPR release, which implied LPR release plays an indispensable role in traditional combination surgical treatments. ...
Article
Full-text available
Purpose: Recurrent patellar dislocation (RPD) is the most common complication of patellar instability and the medial patellofemoral ligament (MPFL) reconstruction has become its reference treatment. Lateral patellar retinaculum (LPR) release used to be performed in association with MPFL reconstruction. The aim of this study was to investigate the added values of MPFL reconstruction plus LPR release for RPD. Methods: After Institutional Review Board approval, RPD patients from October 2014 to April 2019 were randomly assigned into two groups (isolated MPFL reconstruction [Group I] and MPFL reconstruction plus LPR release [Group II]) and prospectively assessed until 12 months after surgery. Knee joints with flexion of 20° were scanned by a 64-row CT scanner. Congruence angle (CA), patella tilt angle (PTA), lateral patellofemoral angle (LPFA), tibial tuberosity-trochlear groove distance and patellar tilt with the quadriceps relaxed and contracted were measured. Knee function was assessed by Lysholm knee score and International Knee Documentation Committee (IKDC) score. Patients were followed up for at least 12 months. Results: A total of 87 RPD patients (45 for Group I and 42 for Group II) were selected in this study. Preoperative clinical characteristics were not significantly different across groups. No serious complications were noted in either group. It was statistically insignificant between the two group patients in terms of postoperative patella associated measurements (P > 0.05 for all). The Lysholm score and IKDC score of Group I (84.5 ± 7.1 and 87.9 ± 7.2) were significantly less than that of Group II (89.7 ± 8.7 and 93.1 ± 7.7), which indicated the better knee function of Group II. Conclusion: LPR release plus MPFL reconstruction provides additional benefits compared with isolated MPFL reconstruction in knee function. A combination of surgical treatments for RPD should be recommended.
... Similarly, Damasena et al. [24] and Mykashima et al. [25] in their papers reported that the return to sport at the same level is often an issue: they, respectively, found that only 10% and 54% of patients returned to play at the same level as before their injury. ...
Article
Full-text available
Purpose The aim of this study was to evaluate the clinical outcomes of patients treated with anatomic medial patellofemoral ligament (MPFL) reconstruction with and without tibial tuberosity osteotomy (TTO). Correlations between patient's age, gender, pre-injury physical activity and the achieved results were investigated as secondary endpoints. Methods An observational retrospective study with prospective collected data was performed. Inclusion criteria were: treatment with anatomic MPFL reconstruction with gracilis tendon according to Schӧttle’s technique performed between 2011 and 2017; associated TTO as unique accessory procedure; skeletal joint maturity; a minimum follow-up of 12 months after surgery. Clinical outcomes were assessed with the Kujala, Lysholm and Tegner scores. Results Forty patients (42 knees) were included, 64% of them underwent TTO. The Kujala score significantly improved from 47.4 ± 17.6 preoperatively to 89.4 ± 13.6 postoperatively ( p < 0.01). The average Lysholm score was 45.6 ± 20.5 preoperatively: it showed a significant increase to 89.8 ± 12.8 postoperatively ( p < 0.01). Pre-injury mean Tegner was 5.9 ± 1.8, while it dropped to 3.0 ± 1.6 after injury. After surgery, Tegner resulted 4.9 ± 1.6. Forty-three percent of patients regained the pre-injury sport activity level. Redislocation rate was 2.4%. Conclusion Anatomic MPFL reconstruction allows excellent patellar stability recovery, knee functionality improvement, return to Activities of Daily Living and a low redislocation rate. Better results were achieved in younger (under 30 years old) and higher sports activity-level subjects. The TTO association provided clinical results comparable to isolated MPFL reconstructions, suggesting that the two procedures can be safely accomplished together without affecting the positive outcomes. Level of evidence Level IV.
Article
Purpose: No consensus exists on rehabilitation programmes after medial patellofemoral ligament reconstruction (MPFLR) with or without tibial tuberosity osteotomy (TTO). This systematic review examined the content and timeline of rehabilitation (weightbearing, range of motion [ROM] and exercise therapy) and return to sport (RTS), as well as patient-reported outcomes after MPFLR with or without TTO. Methods: The PubMed, Cochrane Library, Web of Sciences, CINAHL and SPORTDiscus databases were searched from inception to December 2021. Studies that reported postoperative rehabilitation programmes and patient-reported outcomes for patients aged ≥ 18 years who underwent MPFLR with or without concomitant TTO were included. Results: Eighty-five studies were included, 57 of which were case series and only one randomised controlled trial on rehabilitation programmes. Non-weightbearing was set within one week post-operatively in approximately 80% of weightbearing programmes for MPFLR without and with TTO. Joint immobilisation was set within one week post-operatively in 65.3% and 93.8% of programmes for MPFLR without and with TTO, respectively. Weightbearing and ROM (≤ 90°) restriction were within three weeks post-operatively for > 50% of the programmes. Quadriceps strengthening was the most cited exercise therapy (33 programmes), most often initiated within two weeks post-operatively. However, few other exercise programmes were cited (only nine programmes). RTS was mostly noted at six months post-operatively (35 programmes). The weighted mean Kujala score was 87.4 points. Conclusion: Regardless of TTO addition to MPFLR, most studies restricted weightbearing and ROM only in the early post-operative period, with seemingly favourable clinical results. Limited information was available on post-operative exercise therapy.
Article
PurposeTo determine the reoperation rate, risk factors for reoperation, and patient-reported outcomes after isolated or combined tibial tubercle transfer and medial patellofemoral ligament reconstruction, for patellofemoral instability surgery.Methods Patient’s records who underwent medial patellofemoral ligament reconstruction and/or tibial tubercle transfer for patellar instability by 35 surgeons from 2002 to 2018 at a single academic institution were retrospectively reviewed using CPT codes. Four-hundred-and-eighty-six patients were identified. Radiographic measurements, demographic parameters, and subsequent revision procedures and their indications were identified. A modified anterior knee pain survey was conducted by mail and with follow-up phone survey.ResultsThe overall rate of reoperation was 120/486 (24.7%). The most common cause for reoperation was removal of hardware 42/486 (8.6%). The rate of reoperation for isolated medial patellofemoral ligament reconstruction 43/226 (19%) was lower than that of isolated tibial tubercle transfer 45/133 (33.8%) or a combined procedure 32/127 (25.2%) (P = 0.007). Woman had a higher rate of reoperation (29.4%) compared to men (15.9%) (P = 0.002). Patients at risk for a revision stabilization procedure included those with severe trochlear morphology (C or D) (6.1%) and those with Caton–Deschamps index > 1.3 (7.3%). Patients who underwent reoperation of any kind had poorer patient-reported outcomes.Conclusion The overall reoperation rate after patellofemoral instability surgery remains high, and any reoperation portends worse patient-reported outcomes. Re-operations for instability are more likely in patients with trochlear dysplasia and patella alta and may benefit from more aggressive initial treatment, such as medial patellofemoral ligament reconstruction and tibial tubercle transfer in combination. Using the results of this study, surgeons will be able to engage in meaningful discussion with patients to counsel patients on expectations postoperatively.Level of evidenceIV.
Article
Background: Patellar instability is frequently encountered in the athletic population. Medial patellofemoral ligament (MPFL) reconstruction is a common strategy to treat recurrent patellar dislocation and demonstrates good clinical outcomes. Purpose/hypothesis: The purpose was to examine return to sport after MPFL reconstruction for patellar instability. We hypothesized that patients would resume athletic activity at a high rate and that a large proportion would return to their preoperative level of performance. Study design: Systematic review and meta-analysis. Methods: A systematic review of the literature was conducted using PubMed and Cochrane Library databases to identify articles reporting return to sport after MPFL reconstruction for recurrent patellar dislocation. Athletes were defined as those reporting a preoperative sport. A random-effects model was used to evaluate return to sport rates, subsequent level, and rate of instability recurrence. Meta-regression was used to compare return to sport rates in patients undergoing MPFL reconstruction without osteotomy compared with those treated with simultaneous tibial tubercle osteotomy or trochleoplasty. Results: In total, 23 articles met inclusion criteria after full-text review. A total of 930 patients were analyzed, including 786 athletes. Women represented 61.3% of all patients. The overall mean age was 21.1 years (range, 9.5-60.0 years), with a mean follow-up time of 3.0 years (range, 0.8-8.5 years). The return to sport rate was 92.8% (95% CI, 86.4-97.6). Patients returned to or surpassed their preoperative level of activity in 71.3% (95% CI, 63.7-78.4) of cases. An osteotomy was performed on 10.5% of athletes. Return to sport did not differ significantly in patients undergoing MPFL reconstruction without osteotomy versus those receiving additional osteotomy (95.4% vs 86.9%; P = .22). Patients returned to sport at a mean of 6.7 months (range, 3.0-6.4 months) postoperatively. Osteotomy did not affect return time. Complications occurred at an overall rate of 8.8%. The most common complication was recurrence of instability (1.9%; 95% CI, 0.4-4.0). The Kujala score was reported by 13 studies, with pre- and postoperative combined means of 60.3 and 90.0, respectively. Conclusion: MPFL reconstruction is an effective and reliable treatment in the setting of patellofemoral instability. Surgeons can counsel their patients that they can expect a high rate of return to sport after MPFL reconstruction surgery alone or with concomitant osteotomy.
Article
Purpose To examine the indications and outcomes of medial patellofemoral ligament (MPFL) reconstruction with or without tibial tubercle osteotomy (TTO) in treating recurrent or habitual patella dislocation with increased tibial tuberosity-trochlear groove (TT-TG) distance. Methods A literature search was performed on the established medical databases Cochrane central, PubMed/MEDLINE, EMBASE, Web of science. Inclusion criteria were as follow: skeletal mature patients with recurrent or habitual patella dislocation and increased TT-TG distance; treating with MPFL reconstruction combined with TTO procedure or isolated MPFL reconstruction; clinical outcomes and complications reported. Each study was assessed for quality and level of evidence. General characteristics, indications, surgical techniques, TT-TG distance, clinical results, imaging evaluation and complications of each study were recorded. Results Nine studies consisting of 288 knees met the inclusion criteria. Average of Coleman scores was 71.56 (ranged from 55 to 83). The threshold of increased TT-TG distance ranged from 16 to 20 mm of included studies. And similar good postoperative outcomes were reported in patients with increased TT-TG distance treating with MPFL reconstruction with or without TTO procedure. The mean postoperative Lysholm score ranged from 75.0 to 94.7 (I²=87.6%) in isolated MPFLR group, and from 85.0 to 87.6 (I²=16.3%) in TTO with MPFLR group. Similar postoperative congruence angle (CA) were reported in both groups as well. Postoperative redislocation rate ranged from 0 to 4.2% in TTO with MPFLR group and no redislocation was found in isolated MPFLR group. Postoperative apprehension sign was only reported in isolated MPFL reconstruction. Conclusion The outcomes of MPFL reconstruction with or without TTO treating recurrent or habitual patella dislocation with increased TT-TG distance appeared to be similar. However, this study was limited by the considerable heterogeneity, variety of techniques, variety of TT-TG distances, and the variability of patella alta and trochlear dysplasia among the included studies.
Article
Introduction Medial patellofemoral ligament (MPFL) reconstruction is the procedure of choice for lateral patellar dislocation. However, studies depicting the long terms results of this procedure is lacking. The present study was conducted to evaluate the functional outcomes after MPFL reconstruction at a minimum of five years follow-up. Methods This study was retrospective evaluations of patients who underwent MPFL reconstruction by basket weave method. A total of 35 patients (37 knees) with isolated MPFL tear who met the inclusion criteria were included in this study. These patients were assessed for functional outcome scores including Kujala score, International Knee Documentation Committee (IKDC) score, Lysholm score and Tegner activity score at a minimum follow-up of 5 years. Results The mean follow-up was 81.57 ± 16.07 months and mean age of patients was 19.56 ± 8.02 years. There was no re-dislocation in any of the patients but 4 patients had apprehension test positive (10.81%). The mean Kujala score, IKDC score and Lysholm score preoperatively and postoperatively after MPFL reconstruction were 62.20 ± 16.86 and 90.32 ± 16.42 respectively (p < 0.0001); 58.62 ± 14.34 and 85.15 ± 7.65 respectively (p < 0.0001); 68.21 ± 10.72 and 95.30 ± 8.02 respectively (p < 0.0001) at the five-year follow-up. Mean Tegner score pre-injury and post-surgery was 6.23 ± 2.10 and 5.82 ± 1.90 respectively (p = 0.38) at a mean follow-up of five years. Conclusions MPFL reconstruction surgery for isolated MPFL tears without any associated bony deformity, or soft tissue alterations has a good long-term functional outcome.
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Background: Patients with patellar instability and a tibial tubercle-trochlear groove (TT-TG) distance ≥20 mm may be candidates for distal tubercle realignment surgery. Although this variable has proven valuable in predicting recurrent dislocations, it is not individualized to patient size, bony structure, or patellofemoral mechanics. Purpose: To develop a patellar instability ratio (PIR) that predicts the risk of recurrent instability based on the TT-TG distance to patient-specific anatomy. Study design: Cohort study; Level of evidence, 3. Methods: On magnetic resonance imaging scans of 59 knees with patellar instability, the TT-TG distance, tibial tubercle-posterior cruciate ligament (TT-PCL) distance, sagittal patellar length (PL), sagittal trochlear length (TL), axial patellar width (PW), and axial trochlear width (TW) were calculated by 2 observers in a blinded and randomized fashion. Patients were divided into 2 groups: those with a single dislocation and those with multiple (≥2) dislocations. The ability of the TT-TG and TT-PCL distances as well as the 8 different ratios to predict recurrent instability was assessed by calculating odds ratios (ORs), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each measure. Results: Twelve knees (20%) experienced a single dislocation, while 47 (80%) sustained multiple dislocations. A TT-TG distance ≥20 mm was predictive of recurrent instability (OR, 5.38; P = .29). The highest ORs for recurrent instability were noted for a TT-TG/PW ≥0.4 (OR, 7.37; P = .02) and a TT-TG/TW ≥0.5 (OR, 8.88; P = .04). The sensitivity, specificity, and PPV of a TT-TG/PW ≥0.4 were 62%, 83%, and 94%, respectively, while those of a TT-TG/TW ≥0.5 were 45%, 92%, and 95%, respectively. The sensitivity, specificity, and PPV for a TT-TG distance ≥20 mm were 21%, 100%, and 100%, respectively. Conclusion: Two novel PIRs (TT-TG/TW and TT-TG/PW) were identified and found to be more predictive of recurrent instability than the TT-TG distance alone. Each ratio takes into account patient-specific anatomy and can be measured in an accurate and reliable fashion by clinicians. These PIRs are a step toward overcoming some of the limitations of using the TT-TG distance in isolation. Further investigation into the clinical applications and utility of the TT-TG/TW is warranted.
Article
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Tibial tubercle (TT) transfer and medial patellofemoral ligament (MPFL) reconstruction are used after patellar dislocations. However, there is no objective evidence to guide surgical decision making, such as the ability of MPFL reconstruction to restore normal behavior in the presence of a lateralized TT. MPFL reconstruction will only restore joint contact mechanics and patellar kinematics for TT-trochlear groove (TG) distances up to an identifiable limit. Controlled laboratory study. Eight fresh-frozen cadaveric knees (mean TT-TG distance, 10.4 mm) were placed on a testing rig. Individual quadriceps heads and the iliotibial band were loaded with 205 N in physiological directions using a weighted pulley system. Patellofemoral contact pressures and patellar tracking were measured at 0°, 10°, 20°, 30°, 60°, and 90° of flexion using pressure-sensitive film and an optical tracking system. The MPFL attachments were marked. TT osteotomy was performed, and a metal T-plate was fixed to the anterior tibia with holes at 5-mm intervals for TT fixation. The anatomic TT position was restored after plate insertion. The TT was lateralized in 5-mm intervals up to 15 mm, with pressure and tracking measurements recorded. The MPFL was transected and all measurements repeated before and after MPFL reconstruction using a double-stranded gracilis tendon graft. Data were analyzed using repeated-measures ANOVA, Bonferroni post hoc analysis, and paired t tests. MPFL transection significantly elevated lateral patellar tilt and translation and reduced mean medial contact pressures during early knee flexion. These effects increased significantly with TT lateralization. MPFL reconstruction restored patellar translation and mean medial contact pressures to the intact state when the TT was in anatomic or 5-mm lateralized positions. However, these were not restored when the TT was lateralized by 10 mm or 15 mm. Patellar tilt was restored after 5-mm TT lateralization but not after 10-mm or 15-mm lateralization. Considering the mean TT-TG distance in this study (10.4 mm), findings suggest that in patients with TT-TG distances up to 15 mm, patellofemoral kinematics and contact mechanics can be restored with MPFL reconstruction. However, for TT-TG distances greater than 15 mm, more aggressive surgery such as TT transfer may be indicated. This provides guidance to surgeons as to the threshold at which MPFL reconstruction may satisfactorily restore patellofemoral mechanics, beyond which more invasive surgery such as TT transfer may be indicated. © 2015 The Author(s).
Article
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Background: With improved understanding of the biomechanical importance of the medial patellofemoral ligament (MPFL), its reconstruction for patellar dislocation has become increasingly popular. The aim of this systematic review was to critically determine the effectiveness of MPFL reconstruction for patellar dislocation. Hypothesis: MPFL reconstruction for patellar dislocation leads to a low redislocation rate with improved Kujala scores. Study Design: Systematic review; Level of evidence, 4. Methods: A literature search was performed using Embase and Medline (Ovid) databases. Inclusion criteria included first-time and recurrent patellar dislocation, subluxation, or persistent instability with a minimum follow-up of 12 months and documentation of postoperative redislocation rate or Kujala score. The studies were systematically appraised, and a meta-analysis was performed. Results: Twenty-two studies were included: 2 randomized controlled trials, 3 parallel case series, and 17 case series. There were a total of 655 knees in the review, with an age range at time of surgery from 11 to 52 years. The pooled postoperative redislocation rate from all 17 case series showed a mean of 2.44%. The pooled preoperative Kujala scores from 12 case series showed a mean of 51.6 (95% CI, 46.71-56.49). The pooled postoperative Kujala scores from 16 case series showed a mean of 87.77 (95% CI, 85.15-90.39). Conclusion: Although the studies were of low quality, the meta-analysis of 17 case series shows that MPFL reconstruction for recurrent patellar dislocation results in a significant improvement in Kujala scores, a low redislocation rate, and acceptable complication rate. Randomized trials would be needed to draw influences on the superiority of MPFL reconstruction compared with other treatments.
Article
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Over the long term, acute patellar dislocations can result in patellar instability, with high recurrence rates after nonoperative treatment. To compare the results of operative (reconstruction of the medial patellofemoral ligament [MPFL]) versus nonoperative treatment of primary patellar dislocation. Randomized controlled trial; Level of evidence, 1. Thirty-nine patients (41 knees) (mean age, 24.2 years; range, 12-38 years) with acute patellar dislocation were randomized into 2 groups. One group was treated nonoperatively with immobilization and physiotherapy, the other was treated surgically with MPFL reconstruction; both groups were evaluated with minimum follow-up of 2 years. The Kujala questionnaire was applied to assess pain and quality of life, and recurrence was evaluated. Pearson χ(2) or Fisher exact test was used in the statistical evaluation. The statistical analysis showed that the mean Kujala score was significantly lower in the nonoperative group (70.8), when compared with the mean value of the surgical group (88.9; P = .001). The surgical group presented a higher percentage of "good/excellent" results (71.43%) on the Kujala score when compared with the nonoperative group (25.0%; P = .003). The nonoperative group presented a large number of recurrences and subluxations (7 patients; 35% of cases), whereas there were no reports of recurrences or subluxations in the surgical group. Treatment with MPFL reconstruction using the patellar tendon produced better results, based on the analyses of posttreatment recurrences and the better final results of the Kujala questionnaire after a minimum follow-up period of 2 years.
Article
We examined an39 patients (45 knees) who had undergone Elmslie-Trillat procedure for recurrent or habitual dislocation of the patella with a follow-up of more than ten years. The mean age at the time of surgery was 18.4 years; the mean follow-up was 161 months (120 to 238). Using Fulkerson’s functional knee score, 41 knees (91%) had an excellent or good result at a mean follow-up of 45 months, and this was maintained in 29 (64%) at the final review. The main cause of deterioration in the clinical results was the onset or worsening of patellofemoral joint pain, not patellar instability.
Article
During the past 3 decades, the surgeons of Lyon have developed a vast experience dealing with patellofemoral problems. The “Lyon School,” as it may be called, addresses episodic patellar instability using anatomical principles based on the teachings of Dejour and Walch. Under this theory, trochlear dysplasia is the fundamental anatomical abnormality, without which recurrent patellar instability is very rare. Trochlear dysplasia causes a flat upper portion of the trochlear groove, usually because of a prominent floor as opposed to deficient sidewalls, so that joint reaction forces are increased but lateral constraint is reduced. But the dysplasia itself is rarely addressed directly. Instead, surgical treatment addresses each of 3 principal factors whenever it is present: tibial tubercle–trochlear groove offset, patella alta, and patella tilt. This article presents an algorithm for treating episodic patellar instability based on the teachings of the Lyon School. Although the specifics of the treatment protocol remain subjects of discussion, debate, and study, the protocol has been very successful in the hands of French surgeons.
Article
The purpose of this study was to evaluate the effect of surgical reinsertion of the medial patellofemoral ligament (MPFL) to the adductor tubercle compared with conservative treatment in patients with primary dislocation of the patella. Eighty patients with primary patella dislocation were included in the study. Delayed arthroscopy (mean, 50 days after injury) was performed to assess cartilage injury and status. During arthroscopy, patients were randomized to surgical reinsertion of the MPFL or to conservative treatment. Conservative treatment was use of a brace with 0 degrees to 20 degrees motion for the first 2 weeks after dislocation. Patients were followed up for 2 years. The incidence of recurrent patella dislocation was recorded along with the clinical Kujala scores and Knee Injury and Osteoarthritis Outcome Scores. The redislocation rates were 17% and 20% in the operative and conservative treatment groups, respectively (P = not significant). Kujala scores were 85 and 78 in the operative and conservative treatment groups, respectively (P = .07). The patella stability subscore was significantly higher in the operative group. No difference in Knee Injury and Osteoarthritis Outcome Scores was found. Delayed primary repair of the MPFL by use of an anchor-based reattachment to the adductor tubercle without vastus medialis obliquus repair after primary patella dislocation does not reduce the risk of redislocation nor does it produce any significantly better subjective functional outcome based on the Kujala knee score. Only the specific subjective patella stability score was improved by MPFL repair compared with conservative treatment. Level I, therapeutic randomized controlled trial.
Article
Growing awareness of the biomechanical contribution of the medial patellofemoral ligament has led to an upsurge in the publication of techniques and trials dealing with reconstructive techniques, warranting a review that includes the most recent evidence. Systematic review. The authors undertook a systematic electronic search and rigorous screening process to find and identify published evidence describing the outcomes of medial patellofemoral ligament reconstruction. Fourteen trials were included for analysis. Although they showed generally excellent outcomes for medial patellofemoral ligament reconstruction modalities, there were several recurring weaknesses. Most were small case series, many had limited follow-up, and a majority employed other adjunctive techniques besides medial patellofemoral ligament reconstruction, making it difficult to distinguish the determining factors in their outcomes. There is limited but growing evidence that a medial patellofemoral ligament-based surgical approach to patellofemoral instability leads to excellent functional outcomes.