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ABSTRACT: Debate exists on whether hip labral tears should be surgically repaired, partially resected, or reconstructed. Furthermore, limited data exist regarding the fluid seal properties of hip labrum repair and/or reconstruction with iliotibial band autograft when compared with the labrum-intact condition. Hypothesis/
The purpose of this study was to investigate the fluid seal properties of hip labral repair and reconstruction techniques. We hypothesized that hip labral repair preserves the acetabular labral fluid seal greater than labral tear, partial-resection, and reconstruction conditions.
Controlled laboratory study.
Six human cadaveric hemipelvises were dissected of all soft tissue, leaving the hip capsule intact. Fluid efflux was measured under 5 conditions using a custom fluid infusion device: (1) hip labrum intact, (2) labral tear, (3) labral repair with suture anchors, (4) partial labral resection, and (5) labral reconstruction using ipsilateral iliotibial band autograft. Joint fluid expression was measured as flow rate under 3 different pressure settings (2, 3, and 4 psi). Statistical differences between conditions were assessed using 2-way, repeated-measures analysis of variance. The Student-Newman-Keuls (SNK) multiple comparison test was used to determine differences between levels.
There was a significant increase in fluid efflux with a simulated labral tear (0.54 ± 0.3 mL/sec) when compared with the intact hip labrum condition (0.006 ± 0.008 mL/sec, P < .05). The labrum-repaired condition (0.21 ± 0.2 mL/sec) demonstrated significantly less fluid efflux when compared with the labral-tear condition. Hip labral repair significantly prevented greater fluid efflux when compared with partial labral resection (0.60 ± 0.4 mL/sec) and reconstruction with iliotibial band autograft (0.54 ± 0.3 mL/sec; P < .05). Labral repair did not preserve fluid efflux as effectively as in the labrum-intact condition (0.21 ± 0.2 > 0.006 ± 0.008 mL/sec; P < .05). There was no difference observed in fluid efflux between the labral reconstruction, tear, or resection conditions (P > .05).
In this human cadaveric model, hip labral repair outperforms partial labral resection and reconstruction in preserving the joint fluid seal; however labral repair does not restore fluid seal characteristics as effectively as in the labrum-intact condition.
Further prospective studies are needed to determine whether hip labral repair outperforms partial labral resection and/or reconstruction in clinical practice.
The American journal of sports medicine 09/2012; 40(10):2218-23. · 3.61 Impact Factor
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ABSTRACT: Displaced three- and four-part proximal humerus fractures are among the most challenging shoulder conditions to manage. Because of the risk of symptomatic malunion, nonunion, and humeral head osteonecrosis, surgical management is preferred. Locking plate technology has provided an alternative to hemiarthroplasty for certain three- and four-part fracture patterns, even in the setting of osteopenic bone. Prosthetic humeral head replacement has been advocated for head-splitting fractures and fracture-dislocations as well as four-part fractures with significant initial varus displacement (>20°). Technical challenges, including obtaining proper humeral head height, retroversion, and optimal positioning and fixation of the tuberosities, have a substantial effect on patient outcomes.
The Journal of the American Academy of Orthopaedic Surgeons 01/2012; 20(1):17-27. · 2.66 Impact Factor
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ABSTRACT: The objectives of this study were to characterize and compare the vascularity of arthroscopically repaired rotator cuff tendons at short-term and intermediate-term follow-up.
Nineteen patients who underwent arthroscopic rotator cuff repair were prospectively monitored for an average of 21.2 months. Initial baseline, grayscale ultrasound images of the operated-on shoulder were obtained on all patients at 3 months and at a minimum of 10 months postoperatively. Perflutren-lipid microsphere contrast (DEFINITY, Lantheus Medical Imaging, North Billerica, MA, USA) was injected after baseline grayscale images and after exercise to obtain contrast-enhanced images of the repair. Three regions of interest--supraspinatus tendon, peribursal tissue, and bone anchor site--were evaluated before and after rotator cuff-specific exercises.
The peribursal tissue demonstrated the greatest blood flow, followed by the bone anchor site and tendon, in pre-exercise and postexercise states. Significantly less blood flow was observed in all regions of interest before exercise (P < .05) and only at the bone anchor site after exercise (P < .001) at latest follow-up compared with the 3-month values. Intratendinous blood flow remained relatively low at both evaluation points after surgical repair.
Preliminary findings suggest that the peribursal tissue and bone anchor site are the main conduits of blood flow for the rotator cuff tendon after arthroscopic repair, with the supraspinatus tendon being relatively avascular. Blood flow of the repaired rotator cuff tendon decreases with time. Furthermore, exercise significantly enhances blood flow to the repaired rotator cuff.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 07/2011; 21(5):597-603. · 1.93 Impact Factor
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ABSTRACT: Operative treatment of displaced midshaft clavicle fractures reportedly decreases the risk of symptomatic malunion, nonunion, and residual shoulder disability. Plating these fractures, however, may trade these complications for hardware-related problems. Low-profile anatomically precontoured plates may reduce the rates of plate prominence and hardware removal.
We compared the outcomes after precontoured and noncontoured superior plating of acute displaced midshaft clavicle fractures. Primary outcomes were rate of plate prominence, rate of hardware removal, and rate of complications. Secondary outcomes were ROM and pain and function scores.
We retrospectively reviewed 52 patients with 52 acute, displaced midshaft clavicle fractures treated with either noncontoured or precontoured superior clavicle plate fixation. Fourteen patients with noncontoured plates and 28 with precontoured plates were available for followup at a minimum of 1 year postoperatively. Postoperative assessment included ROM, radiographs, and subjective scores including visual analog scale for pain, American Shoulder and Elbow Surgeons questionnaire, and Simple Shoulder Test.
Patients complained of prominent hardware in nine of 14 in the noncontoured group and nine of 28 in the precontoured group. Hardware removal rates were three of 14 in the noncontoured group and three of 28 in the precontoured group. Postoperative ROM and postoperative subjective scores were similar in the two groups.
Precontoured plating versus noncontoured plating of displaced midshaft clavicle fractures results in a lower rate of plate prominence in patients who do not undergo hardware removal.
Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
Clinical Orthopaedics and Related Research 03/2011; 469(12):3337-43. · 2.53 Impact Factor
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Edwin R Cadet
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ABSTRACT: Glenohumeral instability is a common cause of shoulder disability. A wide spectrum of causes and presentations can make diagnosing subtle instability very difficult. This article describes clinical evaluation of the glenohumeral joint using pertinent components of the patient history, physical examination, and selective imaging to arrive at the diagnosis of glenohumeral instability in the symptomatic patient.
Orthopedic Clinics of North America 07/2010; 41(3):287-95. · 1.25 Impact Factor
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ABSTRACT: The purpose of this study was to investigate whether supraspinatus tendon failure stress at the footprint can increase by improving the bone density at the rotator cuff footprint in a rat model. Bilateral ovariectomies were performed in twenty-four 4-month-old Sprague-Dawley rats. Half received bisphosphonate (zoledronic acid) and the other half received no treatment (OVX + ZOM and OVX, respectively). Twelve additional rats did not undergo ovariectomy or receive bisphosphonate treatment (CON). All rats were sacrificed at 7 months of age. Quantitative micro-computed tomography was used to assess bone density in the proximal humerus. A series of stress-relaxation tests were performed to assess stiffness and failure stress of the supraspinatus tendon. Bone density in OVX + ZOM was significantly higher at the rotator cuff footprint when compared to CON and OVX rats (p < 0.0001). The supraspinatus tendons in the OVX group were significantly stiffer when compared to the CON and OVX + ZOM groups (p < 0.05). The failure stress of the OVX + ZOM group was significantly greater than the CON and OVX groups (22.89 +/- 4.43 MPa vs. 18.36 +/- 3.16 and 17.70 +/- 4.92, respectively). In conclusion, improving the bone density at the rotator cuff footprint enhances failure stress of the suprapinatus tendon.
Journal of Orthopaedic Research 09/2009; 28(3):308-14. · 2.81 Impact Factor
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ABSTRACT: To survey leaders in sports medicine who perform anterior cruciate ligament (ACL) reconstructions to determine the preferred management when ACL graft contamination occurs.
Survey study of expert opinions and experiences on the management of ACL graft contamination.
We mailed 337 surveys to directors of academic sports medicine programs and graduates from an accredited sports medicine fellowship. The survey questioned the incidence, treatment, and outcome of ACL graft contamination.
Twelve surveys were returned to sender; 196 surgeons responded from the remaining 325 surveys (60%). Forty-nine of 196 (25%) surgeons reported at least 1 contamination during their career. Of those 49, 43 surgeons (88%) had 1 contaminated graft, 5 (10%) had 2, and 1 had 4, for a total of 57 reported contaminated grafts. Of the surgeons who reported a contaminated graft, 22 (45%) performed between 40 and 100 ACL reconstructions annually, and 17 (35%) performed more than 100 ACL reconstructions annually. Forty-three of the 57 (75%) contaminated grafts were managed with cleansing of the graft and proceeding with reconstruction. Ten (18%) were managed by harvesting a different graft, and 4 (7%) were substituted with an allograft. No infections in any of the contaminated grafts were reported. Sixty-five of the 147 (43%) surgeons without graft contamination gave hypothetical management responses. Thirty-eight (58%) would cleanse the graft and proceed with the procedure, 22 (34%) would harvest a different graft, and 5 (8%) would use an allograft.
Surgeons who perform a high volume of ACL reconstruction surgery most often choose graft cleansing as the preferred management for intraoperative ACL graft contamination.
Level V, expert opinion.
Arthroscopy The Journal of Arthroscopic and Related Surgery 12/2005; 21(11):1348-53. · 3.02 Impact Factor
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ABSTRACT: Interface contact pressure between the tendon and bone has been shown to influence healing. This study evaluates the interface pressure of the rotator cuff tendon to the greater tuberosity for different rotator cuff repair techniques.
The transosseous tunnel rotator cuff repair technique provides larger pressure distributions over a defined insertion footprint than do suture anchor techniques.
Controlled laboratory study.
Simulated rotator cuff tears over a 1 x 2-cm infraspinatus insertion footprint were created in 25 bovine shoulders. A transosseous tunnel simple suture technique (n = 8), suture anchor simple technique (n = 9), and suture anchor mattress technique (n = 8) were used for repair. Pressurized contact areas and mean pressures of the repaired tendon against the tuberosity were determined using pressure-sensitive film placed between the tendon and the tuberosity.
The mean contact area between the tendon and tuberosity insertion footprint was significantly greater for the transosseous technique (67.7 +/- 5.8 mm(2)) compared with the suture anchor simple (34.1 +/- 9.4 mm(2)) and suture anchor mattress (26.0 +/- 5.3 mm(2)) techniques (P < .05). The mean interface pressure exerted over the footprint by the tendon was also greater for the transosseous technique (0.32 +/- 0.05 MPa) compared with the suture anchor simple (0.26 +/- 0.04 MPa) and suture anchor mattress (0.24 +/- 0.02 MPa) techniques (P < .05).
The transosseous tunnel rotator cuff repair technique creates significantly more contact and greater overall pressure distribution over a defined footprint when compared with suture anchor techniques.
Stronger and faster rotator cuff healing may be expected when beneficial pressure distributions exist between the repaired rotator cuff and its insertion footprint. Tendon-to-tuberosity pressure and contact characteristics should be considered in the development of improved open and arthroscopic rotator cuff repair techniques.
The American Journal of Sports Medicine 09/2005; 33(8):1154-9. · 3.79 Impact Factor
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ABSTRACT: The purpose of the present study was to determine whether longitudinal growth of the cortex occurs through intramembranous bone formation involving the periosteum or through endochondral bone formation involving the growth plate and to explore the cellular and biochemical mechanisms responsible for this process.
Cortical bone formation was studied in the metaphyses of growing New Zealand White rabbits by means of (1) oxytetracycline labeling and fluorescence microscopy, (2) computer-assisted histomorphometry, (3) osteoblast culture and [(3) H]-thymidine incorporation in the presence of periosteum or periosteum-conditioned medium, and (4) surgical insertion of membranes between the periosteum and the underlying spongiosa.
Within the metaphyseal cortex, oxytetracycline labeling produced fluorescent closed curves outlining enlarging trabeculae derived from coalescing endochondral trabecular bone. In this region of coalescing trabeculae close to the periosteum, osteoblast surface was increased compared with trabeculae farther from the periosteum (p < 0.001). The osteoclast surface did not differ. In vitro, osteoblast proliferation was increased in the presence of periosteum (p < 0.001) or periosteum-conditioned medium (p < 0.001). Surgical insertion of permeable or impermeable membranes between the periosteum and the spongiosa did not prevent cortex formation.
These observations demonstrate that metaphyseal cortical bone is formed by coalescence of endochondral trabecular bone. This coalescence is associated with increased osteoblast surface in the peripheral spongiosa. The increased osteoblast surface could be due to inductive effects of periosteum; in the present study, periosteum stimulated osteoblast proliferation in vitro but was not required for metaphyseal cortical bone formation in vivo. Clinical Relevance: Understanding metaphyseal cortical growth may help to elucidate the pathophysiology of osseous growth disorders in children.
The Journal of Bone and Joint Surgery 09/2003; 85-A(9):1739-48. · 3.27 Impact Factor
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Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 16(4):e6-9. · 1.93 Impact Factor
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ABSTRACT: This study investigated whether a relationship exists between greater tuberosity osteopenia and chronicity of rotator cuff tears. In a retrospective study, anteroposterior radiographs of 28 shoulders in 27 patients who had undergone surgical repair for rotator cuff tears were reviewed. Greater tuberosity osteopenia scores were created using National Institutes of Health digital image software. There was no significant difference in the mean age between patients with minimal to mild rotator cuff tear retraction (63.1 +/- 6.14 years) and patients with moderate to severe rotator cuff tear retraction (63.4 +/- 9.76 years; P = .77). Of the 13 patients with minimal to mild rotator cuff tear retraction, 10 (77%) were women and 3 (23%) were men. Of 14 patients (50%) with moderate to severe rotator cuff tear retraction, 7 were men and 7 were women. The mean greater tuberosity osteopenia score in the 15 patients with moderate to severe retraction (0.48 +/- 0.095) was significantly less than the greater tuberosity osteopenia score in the 13 patients with minimal to mild retraction (0.58 +/- 0.135; P < .05). Furthermore, the mean greater tuberosity osteopenia score in 6 patients with chronic retracted rotator cuff tears (0.48 +/- 0.125) was significantly less than in the 6 patients with acute minimally retracted tears (0.64 +/- 0.119, P < .05). There were significantly greater osteopenic changes in the greater tuberosity in patients with chronic retracted rotator cuff tears. The greater tuberosity osteopenia may affect anchor pullout strength and the healing biology that influences overall rotator cuff repair healing rates.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 17(1):73-7. · 1.93 Impact Factor
