[Show abstract][Hide abstract] ABSTRACT: Purpose:
Historically poor results of survivorship and functional outcomes of patellofemoral arthroplasty (PFA) have been reported in the setting of isolated patellofemoral osteoarthritis. More recently, however, fairly good results of PFA were reported, but the current status of PFA outcomes is unknown. Therefore, a systematic review was performed to assess overall PFA survivorship and functional outcomes.
A search was performed using PubMed, Embase and Cochrane systems, and the registries were searched. Twenty-three cohort studies and one registry reported survivorship using Kaplan-Meier curve, while 51 cohort studies reported functional outcomes of PFA.
Twelve studies were level II studies, while 45 studies were level III or IV studies. Heterogeneity was mainly seen in type of prosthesis and year the cohort started. Nine hundred revisions in 9619 PFAs were reported yielding 5-, 10-, 15- and 20-year PFA survivorships of 91.7, 83.3, 74.9 and 66.6 %, respectively, and an annual revision rate of 2.18. Functional outcomes were reported in 2587 PFAs with an overall score of 82.2 % of the maximum score. KSS and Knee Function Score were 87.5 and 81.6 %, respectively.
This systematic review showed that fairly good results of PFA survivorship and functional outcomes were reported at short- and midterm follow-up in the setting of isolated patellofemoral osteoarthritis. Heterogeneity existed mainly in prosthesis design and year the cohort started.
These results provide a clear overview of the current status of PFA in the setting of isolated patellofemoral osteoarthritis.
Level of evidence:
[Show abstract][Hide abstract] ABSTRACT: Purpose:
During recent years, there has been an intensive growth of interest in the patient's perception of functional outcome. The Forgotten Joint Score (FJS) is a recently introduced score that measures joint awareness of patients who have undergone knee arthroplasty and is less limited by ceiling effects. The aim of this study was to compare the FJS between patients who undergo medial unicompartmental knee arthroplasty (UKA) and patients who undergo total knee arthroplasty (TKA) 1 and 2 years post-operatively.
This prospective study compares the FJS at a minimum of one (average 1.5 years, range 1.0-1.9) and a minimum of 2 years (average 2.5 years, range 2.0-3.6) post-operatively between patients who underwent medial UKA and TKA.
One-hundred and thirty patients were included. Sixty-five patients underwent medial UKA and 65 patients underwent TKA. At both follow-up points, the FJS was significantly higher in the UKA group (FJS 1 year 73.9 ± 22.8, FJS 2 year 74.3 ± 24.8) in contrast to the TKA group (FJS 1 year 59.3 ± 29.5 (p = 0.002), FJS 2 year 59.8 ± 31.5, (p = 0.004)). No significant improvement in the FJS was observed between 1- and 2-year follow-up of the two cohorts.
Patients who undergo UKA are more likely to forget their artificial joint in daily life and consequently may be more satisfied.
Level of evidence:
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Unicompartmental knee arthroplasty (UKA) has gained popularity in patients with isolated unicompartmental osteoarthritis. To our knowledge no systematic review has assessed and compared survivorship of medial and lateral UKA. We performed a systematic review assessing medial and lateral UKA survivorship and comparing survivorship in cohort studies and registry-based studies. METHODS: A search was performed using PubMed, Embase and Cochrane systems. Ninety-six eligible studies reported survivorship, of which fifty-eight reported medial and sixteen reported lateral UKA survivorship. Nineteen cohort studies and seven registry-based studies reported combined medial and lateral survivorship. RESULTS: The five-year, ten-year and fifteen-year medial UKA survivorship was 93.9%, 91.7% and 88.9%, respectively. Lateral UKA survivorship was 93.2%, 91.4% and 89.4% at five-year, ten-year and fifteen-year, respectively. No statistical difference between both compartments was found. At twenty years and twenty-five years survivorship of medial UKA was 84.7% and 80%, respectively, but no studies reported lateral UKA survivorship at these follow-up intervals. Survivorship of cohort studies was not significantly higher compared to registry-based studies at five years (94.3 vs. 91.7, respectively, p=0.133) but was significantly higher at ten years (90.5 vs. 84.1, p=0.015). CONCLUSION: This is the first systematic review that shows no difference in the five-, ten- and fifteen-year survivorship of medial and lateral UKA. We found a lower survivorship in the registry-based studies compared to cohort studies. LEVEL OF EVIDENCE: Systematic Review of level IV studies.
The Knee 10/2015; DOI:10.1016/j.knee.2015.09.011 · 1.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
Biomechanical studies indicate that the tibia shifts medially and has a more valgus orientation in the anterior cruciate ligament (ACL)-deficient knee. However, it is not known whether these differences can be detected on standing radiographs.
To determine whether medial subluxation and more changes in coronal alignment of the tibia are detectable in both weightbearing radiographs and a cadaveric model simulating quiet standing.
Case series; Level of evidence, 4, and Descriptive laboratory study.
Radiographic data were available for a cross-section of 74 patients with unilateral ACL tears. Tibial subluxation and coronal limb alignment were measured on hip-to-ankle weightbearing radiographs. Eight cadaveric knees were mounted on a 6 degree of freedom robot. Mediolateral position and varus-valgus alignment of the tibia relative to the femur were measured in response to 300-N axial compression simulating quiet standing at 5° and 15° of flexion with the ACL intact and sectioned.
Across all 74 patients included in the clinical study, the ACL-injured knee experienced 1.6 ± 2.3 mm (mean ± SD) of medial tibial subluxation compared with the contralateral uninjured knee (P < .001). The 24 patients with isolated ACL rupture exhibited 2.0 ± 1.8 mm of medial subluxation (P < .001). The mean coronal alignment of all 74 patients in the study was 0.7° ± 2.8° varus in the injured limb and 1.3° ± 2.6° varus in the uninjured contralateral limb (P = .0187). In the cadaveric model, the tibia translated 0.4 ± 0.5 mm more medially after sectioning of the ACL at 15° of flexion (P = .0485); however, no changes in coronal alignment were detected.
The tibia shifts medially and is less varus in the ACL-deficient knee on standing radiographs. The medial tibial shift is reproduced in an axially loaded cadaveric model.
Medial tibiofemoral subluxation seen on frontal plane standing radiograph is an underappreciated sequela of isolated ACL rupture. The ability of ACL reconstruction to restore this aspect of ACL injury is not well understood and should be investigated further. Cadaveric models may be used to directly measure the mechanical effect of subtle changes in mediolateral position on articular contact stress as an indicator of the importance of this finding.
The American Journal of Sports Medicine 10/2015; DOI:10.1177/0363546515608473 · 4.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To analyze knees in varying stages of osteoarthritis (OA) for the presence of coronal tibiofemoral (CTF) subluxation and to determine if CTF subluxation severity is related to knee OA worsening.
We retrospectively evaluated CTF subluxation and limb alignment in 113 patients with different stages of knee OA who were being considered for an arthroplasty procedure. Knee OA was classified as "mild" or "severe" according to Kellgren-Lawrence scale. CTF subluxation was measured in the study groups and in 40 knees of healthy controls using software developed specifically on the basis of Iterative Closest Point mathematical algorithm.
Mean CTF subluxation in "mild OA" and "severe OA" groups was 3.5 % (±2) and 3.5 % (±5) of the tibial plateau, respectively. For both the mild and severe OA groups, CTF subluxation was significantly increased compared to the 1.4 % (±1) CTF subluxation in the control group, (p < 0.0001) and (p = 0.012), respectively. However, there was no significant difference in CTF subluxation between the mild OA and severe OA groups (p = 0.75). Limb varus malalignment in mild OA and severe OA groups was 3.6° (±2.2) and 5.3° (±2.6), respectively. Both significantly increased comparing to the 1° (±0.7) control group alignment (p < 0.0001). Varus malalignment in the severe OA group was significantly increased comparing to the mild OA group (p = 0.0003).
CTF subluxation is a radiographic finding related to knee OA which occurs mainly in the early stages of the osteoarthritic process and stagnates as OA progresses.
[Show abstract][Hide abstract] ABSTRACT: Medial unicompartmental knee arthroplasty (UKA) is a procedure designed for resurfacing the medial compartment in isolated medial compartment degenerative joint disease. Many long-term studies have reported the success of UKA. Despite recent interest and isolated reports of success, significant issues still exist today with early failure in UKA. Medial UKA is a promising alternative to TKA for isolated medial compartment DJD. Potential advantages of this treatment option compared to TKA include improved patient satisfaction, more consistent return to sporting activities, quicker recovery, decreased complication risk, and greater range of motion. With the introduction of robotic arm tools to help improve accuracy and reliability of implant position we may be able to decrease failure rates in UKAs. In addition, cementless technologies are promising approaches to improve the durability of UKA fixation. Robotic arm techniques coupled with cementless fixation strategies may dramatically reduce the incidence of aseptic loosening in UKA.
Operative Techniques in Orthopaedics 03/2015; 60(2). DOI:10.1053/j.oto.2015.03.003
[Show abstract][Hide abstract] ABSTRACT: Unicompartmental knee arthroplasty (UKA) is an increasingly popular option for the treatment of single-compartment knee osteoarthritis (OA) in adults. Two options for tibial resurfacing during UKA are (1) all-polyethylene inlays and (2) metal-backed onlays.
The aim of this study was to determine whether there are any differences in clinical outcomes with inlay versus onlay tibial components.
We identified 39 inlays and 45 onlays, with average 2.7- and 2.3-year follow-up, respectively, from a prospective robotic-assisted surgery database. The primary outcome was the Western Ontario and McMaster University Arthritis Index (WOMAC), subcategorized by the pain, stiffness, and function subscores, at 2 years postoperatively. The secondary outcome was the need for secondary or revision surgery.
Postoperative WOMAC pain score was 3.1 for inlays and 1.6 for onlays (p = 0.03). For 25 inlays and 30 onlays with both preoperative and postoperative WOMAC data, pain score improved from 8.3 to 4.0 for inlays versus from 9.2 to 1.7 for onlays (p = 0.01). Function score improved from 27.5 to 12.5 for inlays versus from 32.1 to 7.3 for onlays (p = 0.03). Four inlays and one onlay required a secondary or revision procedure (p = 0.18).
We advise using metal-backed onlays during UKA to improve postoperative clinical outcomes.
[Show abstract][Hide abstract] ABSTRACT: Objectives: Recent histological studies have shown that the ACL consists of two different structures: the direct and indirect insertions. The direct insertion is located along the lateral intercondylar ridge and the indirect insertion is ‘lower’ in the notch, adjacent to the posterior articular cartilage. The ‘lower’ position has become more popular for locating the femoral tunnel, as surgeons switch to the anteromedial (AM) portal drilling technique in order to place the graft in the region of the native footprint. However, a recent registry-based outcomes study has reported a 1.5 times higher graft failure rate for AM portal versus traditional transtibial techniques. The objective of this study was to investigate the load characteristics of the native ACL in the regions of the direct and indirect insertions. We hypothesized that the direct insertion would carry more load than the indirect insertion.
[Show abstract][Hide abstract] ABSTRACT: Robotic-assisted unicompartmental knee arthroplasty (UKA) is accurate and repeatable. Lateral UKA is still considered a challenge, as the lateral side of the knee has different anatomy and kinematics compared with the medial side. The lateral compartment of the knee is less constrained than the medial compartment and is therefore less tolerant for mobile-bearing implants and ACL deficiency. However, the long-term outcomes of lateral UKA are scarce. Moreover, the impact of patellofemoral joint degeneration on the outcome of lateral UKA is unknown. We report our preliminary results with fixed bearing robotic-assisted lateral UKA, which are encouraging in the short term.
Sports Medicine and Arthroscopy Review 12/2014; 22(4):223-8. DOI:10.1097/JSA.0000000000000053 · 1.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose:
In an effort to minimize graft impingement among various ACL deficient states, we sought to quantitatively determine requirements for bone resection during notchplasty with respect to both volumetric amount and location.
A validated method was used to evaluate Magnetic Resonance Imaging scans. We measured the ATT of the medial and lateral compartments in the following four states: intact ACL (27 patients), acute ACL disruption; <2 months post-injury (76 patients), chronic ACL disruption; 12 months post-injury (42 patients) and failed ACL reconstruction (75 patients). Subsequently, 11 cadaveric knees underwent Computed Tomography (CT) scanning. Specialized software allowed virtual anterior translation of the tibia according to the average ATT measured on MRI. Impingement volume was analyzed by performing virtual ACLRs onto the various associated CT scans. Location was analyzed by overlaying an on-screen protractor. The center of the notch was defined as 0°.
Average impingement volume changed significantly in the various groups compared to the intact ACL group (acute 577 ± 200 mm(3), chronic 615 ± 199 mm(3), failed ACLR 678 ± 210 mm(3), p=0.0001). The location of the required notchplasty of the distal femoral wall border did not change significantly. The proximal femoral border moved significantly towards the center of the notch (acute 8.6° ± 4.8°, chronic 7.8° ± 4.2° (p=0.013), failed ACLR 5.1° ± 5.9° (p=0.002)).
Our data suggests that attention should be paid peri-operatively to the required volume and location of notchplasty among the various ACL deficient states to minimize graft impingement.
The Knee 09/2014; 21(6). DOI:10.1016/j.knee.2014.08.011 · 1.94 Impact Factor