Characterization of the orientation and isometry of Humphrey's ligament.

OBJECTIVES/PURPOSE: The purpose of this study was to examine the effect of flexion angle on isometry and fiber obliquity of the anterior meniscofemoral ligament (Humphrey's ligament (HL)). METHODS: Following a medial parapatellar arthrotomy on 7 fresh frozen cadavers, the insertion points of the anterolateral (AL) and posteromedial (PM) bundles of the PCL, and HL were identified. Using a 9mm circular software tool, virtual fibers were created. Within each virtual graft, a central fiber was calculated and used to generate anisometry profiles for the AL and PM bundles and HL at flexion angles of 0°, 30°, 60°, 90°, and 120°. Previously validated computer navigation software was used to re-create three dimensional bundles to measure fiber obliquity in the sagittal, frontal, and axial planes. RESULTS: HL length increased with knee flexion from 0 to 120°, and underwent similar length changes as the PCL bundles. In full extension and at 90°, the average length of the PM and AL bundles were not statistically different (p=0.13 and p=0.85 respectively). From 0 to 120°, the PM bundle was the most isometric, but the anisometry profile was statistically similar to the AL bundle and HL. In general, HL and the PM bundle had similar graphic trends in terms of fiber obliquity in all planes. CONCLUSIONS: Using computer navigation, we have demonstrated that HL has similar isometry profiles as the PM and AL bundles of the PCL, and "mirrored" the obliquity of the PM bundle in all planes throughout flexion to 120°.

Rotator cuff tear arthropathy: evaluation, diagnosis, and treatment: AAOS exhibit selection.

Rotator cuff tear arthropathy encompasses a broad spectrum of pathology, but it involves at least three critical features: rotator cuff insufficiency, degenerative changes of the glenohumeral joint, and superior migration of the humeral head. Although many patients possess altered biomechanics of the glenohumeral joint secondary to rotator cuff pathology, not all patients develop rotator cuff tear arthropathy, and thus the exact etiology of rotator cuff tear arthropathy remains unclear. The objectives of this manuscript are to (1) review the biomechanical properties of the rotator cuff and the glenohumeral joint, (2) discuss the proposed causes of rotator cuff tear arthropathy, (3) provide a brief review of the historically used surgical options to treat rotator cuff tear arthropathy, and (4) present a treatment algorithm for rotator cuff tear arthropathy based on a patient's clinical presentation, functional goals, and anatomic integrity.

From wall graft to roof graft: reassessment of femoral posterior cruciate ligament positioning.

In many technique guides for posterior cruciate ligament (PCL) reconstruction, the PCL is depicted on the wall of the medial femoral condyle (MFC). We hypothesized that most of the anterolateral (AL) bundle originates on the roof of the intercondylar notch (ICN), not on the wall. Using a surgical navigation system, we delineated and morphed in the computer the entire PCL footprint-the AL bundle, the posteromedial (PM) bundle, and the Humphrey ligament (HL)-of 7 fresh-frozen cadaveric specimens. A clock face was defined in the en face view, with the 12-o'clock axis pointing anteriorly through the top of the notch and the roof being the region between 10 o'clock and 2 o'clock. The AL-bundle, PM-bundle, and HL positions were calculated in terms of this clock-face definition. Mean centroids (o'clock position) over all specimens of AL bundle, PM bundle, and HL were, respectively, 10:49, 9:43, and 9:00 on the left knee and 1:11, 2:17, and 3:00 on the right knee. Mean areas were 63 mm(2) (AL bundle), 63 mm(2) (PM bundle), and 45 mm(2) (HL). In 5 of the 7 specimens tested, 100% of the AL bundle originated on the roof of the ICN. Conversely, 66% of the PM bundle and 100% of the HL inserted on the wall of the MFC rather than on the intercondylar roof. Using computer navigation software, we determined that most of the AL bundle originates on the roof of the ICN and that the PM bundle is centered near the transition between the roof and the wall of the MFC. These findings contradict the depiction in most technique guides for PCL reconstruction. Implant companies and surgeons should modify their techniques to shift PCL graft tunnels from the wall of the MFC to the roof of the ICN.

Effect of femoral socket position on graft impingement after anterior cruciate ligament reconstruction.

BACKGROUND: Despite improved biomechanical stability and kinematics with anatomic anterior cruciate ligament (ACL) reconstruction, concerns regarding notch impingement of the graft have persisted, particularly with increasingly anterior tibial tunnel position. The potentially mitigating effect of anatomic femoral socket position, however, has not been evaluated. HYPOTHESIS: Placement of the femoral socket in the central or posterolateral bundle footprint reduces the risk and magnitude of graft impingement after ACL reconstruction compared with placement in the anteromedial bundle footprint. STUDY DESIGN: Controlled laboratory study. METHODS: This study employed computer-assisted navigation in a cadaveric model to evaluate the effect of tibial and femoral tunnel position on ACL graft impingement. Sixteen cadaveric knees were tested using the Praxim ACL Surgetics Navigation System, with the tibial tunnel positioned in the footprint of the anteromedial bundle and the femoral socket placed in the (1) anteromedial bundle footprint, (2) center of footprint, or (3) posterolateral bundle footprint. The amount of maximum impingement, angle of initial impingement, and location of graft impingement were documented through a full arc of knee motion. RESULTS: Impingement occurred with all 3 femoral socket positions, but the mean angle of impingement with the anteromedial femoral position (42.8° ± 26.4°) was significantly greater (P < .003) than the mean angles of impingement with the central femoral position (19.4° ± 19.2°) and the posterolateral bundle femoral position (16.7° ± 13.3°). CONCLUSION: Although notch impingement was seen in all femoral socket locations with an anteromedial tibial socket position, femoral socket position in a central or posterolateral bundle location may reduce the risk and magnitude of graft impingement after ACL reconstruction. Additional studies are necessary to determine the influence of these different constructs on graft isometry and knee kinematics. CLINICAL RELEVANCE: Anatomic femoral socket position in the center of the native ACL footprint may reduce the risk and magnitude of notch impingement compared with an anteromedial bundle position with ACL reconstruction.

Rheumatoid synovectomy: does the surgical approach matter?

BACKGROUND: Surgical synovectomy relieves pain in patients with rheumatoid arthritis (RA). The comparative effect of arthroscopic versus open synovectomy on pain reduction, recurrence of synovitis, radiographic progression, and need for subsequent total joint arthroplasty (TJA) is unclear. Whether synovectomy relieves pain in patients with advanced degenerative joint changes is also controversial. QUESTIONS/PURPOSES: We therefore asked whether arthroscopic synovectomy resulted in equal pain relief, recurrence rates, rates of radiographic progression, likelihood of arthroplasty, and whether surgical synovectomy relieved pain and halted progression in the presence of advanced RA. METHODS: We searched PubMed, Cochrane Database of Systematic Reviews, and BMJ Clinical Evidence. After appropriate selection criteria, 58 studies were identified, including 36 on open synovectomy and 22 on arthroscopic synovectomy, with a total of 2589 patients and a mean followup of 6.1 years. Meta-analysis was performed for knees and elbows, comparing open versus arthroscopic synovectomy. Variables included the percentage of patients with pain reduction, recurrence of synovitis, radiographic progression, and need for subsequent TJA or arthrodesis. RESULTS: Patients undergoing arthroscopic synovectomy had similar pain reduction, but more frequent recurrences of synovitis and radiographic progression than patients with open synovectomy. Patients undergoing arthroscopic synovectomy had similar and decreased risks of subsequent elbow and knee arthroplasties, respectively. Advanced preoperative radiographic RA did not correlate with worse pain scores nor increased need for subsequent arthroplasty when compared with minimal degenerative joint changes. CONCLUSIONS: Arthroscopic synovectomy, while providing similar pain relief, may place patients at higher risk for recurrence and radiographic progression of RA. Advanced preoperative degenerative joint disease should not be an absolute contraindication to synovectomy. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Long-term followup of total hip arthroplasty in patients with cerebral palsy.

BACKGROUND: Patients with cerebral palsy (CP) are at risk for hip arthrosis secondary to the loss of joint congruity. QUESTIONS/PURPOSES: We asked whether THA relieved pain, improved function, and provided durable improvements. METHODS: We retrospectively identified 56 patients (59 hips) with CP who had THAs for painful hips. Chart review determined the preoperative, postoperative, and current functional levels. All patients or caregivers completed a questionnaire, including a modified Gross Motor Function Classification System mobility scale and qualitative reports of pain and satisfaction. Pain levels were measured on a visual analog scale at three times: preoperative, postoperative, and current. The average age of the patients at the time of surgery was 30.6 years. Minimum followup was 2 years (average, 9.7 years; range, 2-28 years). RESULTS: Pain relief was obtained in all patients. All patients returned to preoperative function (59) and 52 patients returned to prepain functional status (88%). Seven patients underwent acetabular component revisions, and two patients had a femoral stem component revision. The 2-year implant survival was 95%, and 10-year survivorship was 85%. CONCLUSIONS: THA can provide durable relief and improved function in patients with CP with severe coxarthrosis. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Symptomatic glenoid loosening complicating total shoulder arthroplasty.

Glenoid component loosening is one of the most common causes of failed total shoulder arthroplasty. Previous reports indicate that it is desirable to reimplant the glenoid component during revision shoulder arthroplasty. The purpose of our study was to retrospectively evaluate the satisfaction of patients undergoing glenoid revision (reimplantation or resection) following total shoulder replacement specifically for symptomatic glenoid loosening. Twenty-eight shoulders that developed symptomatic glenoid loosening following primary total shoulder arthroplasty were included in the study. Patients were retrospectively evaluated at a minimum of 2 years postoperatively. Patients either underwent resection followed by reimplantation of the glenoid component (13) or resection of the component with or without bone grafting (15). Each patient was evaluated with the UCLA Shoulder Scale and the Constant-Murley Shoulder Assessment. There were seven excellent, 13 good, five fair and three poor results on the UCLA score. Functional outcome scores trended higher in the reimplantation group but were not statistically significant. Both groups reported equal pain relief and satisfaction. Five out of 15 patients underwent arthroscopic resection of the glenoid, and these patients scored as well on the UCLA and Constant scores as the reimplantation group. When symptomatic glenoid loosening is the indication for revision total shoulder replacement, patients tend to achieve good to excellent results. Though functional scores were slightly higher in the reimplantation group, satisfaction was equally high in both groups. Resection, when indicated, should be performed arthroscopically as this improved functional outcome in our series.