Sommer Hammoud

Zone of Injury of the Medial Patellofemoral Ligament After Acute Patellar Dislocation in Children and Adolescents

Background: Patellar dislocation is a common traumatic injury in the pediatric and adolescent population. The primary constraint to lateral subluxation and dislocation of the patella is the medial patellofemoral ligament (MPFL), which serves to resist lateral translation of the patella. Injury to the MPFL may predispose to recurrent dislocation but the anatomic site of injury is poorly characterized in children and adolescents. Purpose: The authors addressed 2 questions: (1) What is the zone of injury to the MPFL in a pediatric/adolescent population after primary patellar dislocation? (2) What is the location of the femoral attachment of the MPFL with respect to the growth plate? Study Design: Cohort study (prevalence); Level of evidence, 2. Methods: Patients were eligible if they were ≤18 years of age and suffered a recent patellar dislocation characterized by magnetic resonance imaging (MRI) findings of high T2-signal intensity in the lateral femoral condyle. Patients were excluded if they had a history of prior dislocations, prior knee surgery, or congenital dislocation. Two musculoskeletal radiologists and an orthopaedic resident reviewed MRI scans of 43 children. The MPFL was divided into 3 zones: patellar insertion, femoral insertion, and midsubstance. The zone of injury was confirmed by the presence of associated soft tissue edema on short tau inversion recovery sequences and the distance from the MPFL insertion to the medial distal femoral growth plate was measured. Associated injuries were noted and the Insall-Salvati ratio was measured. Results: The MPFL injury was isolated to the patellar attachment in 61% of patients and to the femoral attachment in 12%. Twelve percent of patients had injury at both the patellar and femoral attachments. Six percent had no identifiable MPFL injury and 9% had combinations of midsubstance and either patellar or femoral attachment injuries. The kappa value for injury determinations was 0.71, indicating substantial concordance. The MPFL insertion site averaged 5 mm distal to the medial physis. Eighty-six percent of patients had an MPFL insertion distal to the growth plate, 7% had an insertion at the physis, while only 7% had a proximal insertion. The incidence of associated chondral injuries, the value of the Insall-Salvati ratio, and the location of MPFL insertion did not vary significantly with location of MPFL injury. Sixteen patients (36%) had MPFL insertions that were within 5 mm (either proximal or distal) of the growth plate. Conclusion: The zone of MPFL injury in a pediatric population after primary patellar dislocation was predominantly isolated to the patellar attachment (61%), in contrast to previous literature. Twelve percent of patients had injury only at the femoral attachment, while 12% of patients had injury to both the patellar and femoral attachments. The remaining 15% had injury at multiple locations or no identifiable injury. The MRI finding that the anatomic insertion of the MPFL is distal to the physis in 93% of patients and that the MPFL is more likely to be injured at the patellar attachment has important implications in the surgical reconstruction of the MPFL in pediatric or adolescent patients.

High Incidence of Athletic Pubalgia Symptoms in Professional Athletes With Symptomatic Femoroacetabular Impingement

PURPOSE The purpose of this study was to identify the incidence of symptoms consistent with athletic pubalgia (AP) in athletes requiring surgical treatment for femoroacetabular impingement (FAI) and the frequency of surgical treatment of both AP and FAI in this group of patients. METHODS Thirty-eight consecutive professional athletes, with a mean age of 31 years, underwent arthroscopic surgery for symptomatic FAI that limited their ability to play competitively. In all cases a cam and/or focal rim osteoplasty with labral refixation or debridement was performed. In 1 case concomitant intramuscular lengthening of the psoas was performed. Retrospective data regarding prior AP surgery and return to play were collected. RESULTS Thirty-two percent of patients had previously undergone AP surgery, and 1 patient underwent AP surgery concomitantly with surgical treatment of FAI. No patient returned to his previous level of competition after isolated AP surgery. Thirty-nine percent had AP symptoms that resolved with FAI surgery alone. Of the 38 patients, 36 returned to their previous level of play; all 12 patients with combined AP and FAI surgery returned to professional competition. The mean duration before return to play was 5.9 months (range, 3 to 9 months) after arthroscopic surgery. CONCLUSIONS There is a high incidence of symptoms of AP in professional athletes with FAI of the hip. This study draws attention to the overlap of these 2 diagnoses and highlights the importance of exercising caution in diagnosing AP in a patient with FAI. LEVEL OF EVIDENCE Level IV, therapeutic, retrospective case series.

Outcomes of posterior cruciate ligament treatment: a review of the evidence.

Objectives The purpose of this systematic review is to assess the current recommendations in an evidence-based manner with regard to posterior cruciate ligament (PCL) reconstruction. Methods We conducted a systematic review of multiple databases, evaluating studies on the outcomes of PCL treatment in isolation and in the multiligamentous injured knee. Results Twenty-one studies of isolated PCL reconstructions and 10 studies of combined PCL reconstruction were identified for inclusion. Eight studies reported graft failure as an outcome, with an overall rate of 11.6%. Three studies reported outcomes of single bundle PCL reconstruction using hamstring autograft; there were 12 graft failures in 96 reconstructions (12.5%). There were 2 graft failures in a total of 17 combined PCL/anterior cruciate ligament/posterolateral corner reconstructions (11.8%). In the combined PCL studies, return to preinjury activity level ranged from 19 to 68%. In the isolated PCL studies, 50 to 82% of patients were able to return to preinjury activity level. There were no significant differences in functional outcomes (Lysholm and IKDC). From 37% to 70% of patients in the combined PCL studies had a normal posterior drawer test at final follow-up. One study showed a significant difference in the mean posterior drawer test side-to-side difference between the 7-strand and 4-strand hamstring autograft groups (1.7 vs. 3.7 mm, P<0.05). Conclusions Currently, firm recommendations on what treatment or technique to choose cannot be given based upon the available literature. There is a need for higher-quality clinical studies to guide treatment decisions. Generally good results are reported after PCL reconstruction, but the long-term studies available suggest that normal stability in the majority of patients is not restored.

Augmenting the articular cartilage-implant interface: functionalizing with a collagen adhesion protein

The lack of integration between implants and articular cartilage is an unsolved problem that negatively impacts the development of treatments for focal cartilage defects. Many approaches attempt to increase the number of matrix-producing cells that can migrate to the interface, which may help to reinforce the boundary over time but does not address the problems associated with an initially unstable interface. The objective of this study was to develop a bioadhesive implant to create an immediate bond with the extracellular matrix components of articular cartilage. We hypothesized that implant-bound collagen adhesion protein (CNA) would increase the interfacial strength between a poly(vinly alcohol) implant and an articular cartilage immediately after implantation, without preventing cell migration into the implant. By way of a series of in vitro immunohistochemical and mechanical experiments, we demonstrated that (i) free CNA can bind to articular cartilage, (ii) implant-bound CNA can bind to collagen type II and (iii) implants functionalized with CNA result in a fourfold increase in interfacial strength with cartilage relative to untreated implants at day zero. Of note, the interfacial strength significantly decreased after 21 days in culture, which may be an indication that the protein itself has lost its effectiveness. Our data suggest that functionalizing scaffolds with CNA may be a viable approach toward creating an initially stable interface between scaffolds and articular cartilage. Further efforts are required to ensure long-term interface stability.

The glenoid in total shoulder arthroplasty

Management of glenohumeral arthrosis with a total shoulder prosthesis is becoming increasingly common. However, failure of the glenoid component remains one of the most common causes for failure. Our understanding of this problem has evolved greatly since the first implants were placed in the 1970’s. However glenoid failure remains a challenging problem to address and manage. This article reviews the current knowledge regarding the glenoid in total shoulder arthroplasty touching on anatomy, component design, implant fixation, causes of implant failure, management of glenoid failure and alternatives to glenoid replacement.

Results of Treatment of the Multiple-Ligament-Injured Knee

Knee dislocations are rare injuries, but are among the most serious of all traumatic extremity injuries. Initial assessment of vascular status is critical due to the potential for injury to the popliteal artery. Late complications include decreased range of motion (ROM), instability, pain, and the inability to return to previous activities and sport. Given the rarity and heterogeneity of this injury, high-quality clinical studies and randomized clinical trials are largely lacking to help guide treatment. Continued areas of debate surrounding the operative treatment of the multi-ligament-injured knee include early vs. delayed reconstruction, repair vs. reconstruction of the posterolateral corner (PLC), and preferred treatment of the medial side. Prognostic factors associated with improved outcomes include younger patients, injuries sustained secondary to sports rather than motor vehicle accidents, and the use of functional rehabilitation. The optimal timing for surgical intervention remains controversial. Specific factors on initial assessment that may guide treatment include vascular status, concomitant injuries, and skin condition. Although many authors report improved outcomes with surgical intervention, arthrofibrosis remains an important concern. In general, the specific structures injured dictate early vs. delayed reconstruction. The literature reviewing the outcomes after surgical treatment is difficult to assess and is inconclusive due to several factors, including limited subject number, lack of objective measures, heterogeneity of injury patters, and varying surgical procedures utilized. Here we present the best evidence in the literature regarding the outcomes of treatment of the multi-ligament-injured knee including outcomes specific to the treatment of injuries to the medial side of the knee and the PLC.

Double-Row Capsulolabral Repair

Both open and arthroscopic anterior shoulder stabilization procedures are commonly performed to address shoulder instability and have been shown to be successful in restoring shoulder stability and patient function. However, a critical review of the risk factors for recurrent instability following anterior stabilization is required to determine which patients may benefit from open stabilization, as recurrence rates following arthroscopic stabilization have historically been higher than with open stabilization. Multiple prospective studies have implicated younger patient age, capsular stretching, ligamentous laxity, contact athletics, and glenoid or humeral bone loss as risk factors for arthroscopic anterior shoulder stabilization failure [1–7].