The nonoperative treatment of acute, isolated (partial or complete) posterior cruciate ligament-deficient knees: an intermediate-term follow-up study.

Fifty-seven consecutive patients (58 knees) with an acute, isolated, posterior cruciate ligament (PCL) injury were treated nonoperatively. Clinical, radiographic, and functional assessment was performed at a mean follow-up of 6.9 years (range 2 to 19.3 years) after the initial diagnosis. At the time of initial documentation of the injury, the posterior drawer test was grade A in 17 knees and grade B in 41 knees. The mean preinjury Tegner activity level was 7 (range 4 to 10). At latest follow-up, 38 knees had no pain, 14 had mild pain, and 6 had moderate pain on exertion. Fifty-four knees had no swelling, 3 had mild, intermittent swelling, and 1 had a moderate swelling on exertion. The posterior drawer test was grade A in 14 knees and grade B in 44 knees. The mean Lysholm-II knee score was 85.2 points (range 51 to 100 points) and the mean Tegner activity level was 6.6 (range 3 to 10). Based on Lysholm-II knee scoring system, the results were excellent in 23 knees (40%), good in 30 knees (52%), fair in 2 knees (3%), and poor in 3 knees (5%). No statistically significant correlation (p = 0.097) was seen between the grade of PCL laxity and Lysholm-II knee score. Plain radiographs showed mild (grade I) medial compartment osteoarthritis (OA) in 7 knees, and moderate (grade II) medial compartment OA in 3 knees. Mild patellofemoral OA was seen in 4 knees. We believe that most patients with acute, isolated PCL injuries do well with nonoperative treatment at a mean follow-up of 6.9 years. The level of evidence for this retrospective cohort study is level III.

Effects of small incongruities in a sheep model of osteochondral autografting.

BACKGROUND: Exact reconstruction of an osteochondral defect by autogenous transplantation (mosaicplasty) is difficult given the variation in joint surface contour. Clinical and experimental studies do not show the extent to which incongruity can be tolerated in autografting. HYPOTHESIS: Grafted articular cartilage will hypertrophy to correct the incongruity created by recession of the transplanted surface. STUDY DESIGN: Controlled laboratory study. METHODS: To test the response of grafts to incongruities, osteochondral autografts were transplanted from the trochlea to the femoral condyle in adult male sheep stifle joints. In groups of 6 animals, graft surfaces were placed flush, countersunk 1 mm or countersunk 2 mm, then histologically analyzed 6 weeks after surgery. Cartilage thickness, condition of the articular surfaces, and preservation of hyaline characteristics were the primary features compared. RESULTS: Bony union, vascularization, and new bone formation were present in all grafts. Cartilage-to-cartilage healing did not occur. In flush specimens, cartilage changed minimally in thickness and histologic architecture. The specimens countersunk 1 mm demonstrated significant cartilage thickening (54.7% increase, P <.05). Chondrocyte hyperplasia, tidemark advancement, and vascular invasion occurred at the chondroosseous junction, and the surface remained smooth. Cartilage necrosis and fibrous overgrowth were observed in all grafts countersunk 2 mm. CONCLUSIONS: Minimally countersunk autografts possess a capacity for remodeling that can correct initial incongruities while preserving hyaline characteristics. Grafts placed deeper do not restore the contour or composition of the original articular surface. CLINICAL RELEVANCE: If preservation of normal hyaline cartilage is the objective, thin grafted articular cartilage can remodel, but the tolerance for incongruity is limited and probably less than that reported for an intra-articular fracture.

Timeline of tibial tunnel expansion after single-incision hamstring anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study was to determine the time frame for tibial tunnel expansion in patients undergoing anterior cruciate ligament (ACL) reconstruction with hamstring autografts using an endoscopic technique. Does this expansion occur immediately after surgery or over the first 12 weeks of rehabilitation? TYPE OF STUDY: Observational study involving 10 patients. METHODS: The single incision technique used a transtibial approach for drilling the femoral tunnel. Femoral fixation was accomplished with a closed-loop EndoButton (Acufex, Smith & Nephew; Mansfield, MA) and tibial fixation with a soft tissue screw and washer augmented by a polylactic acid interference screw. Computed tomography (CT) scans were taken in a consistent manner at weeks 1 and 12 after surgery to measure tibial and femoral tunnel expansion. RESULTS: The CT scans showed significant widening of the tibial tunnel between 1 and 12 weeks (mean area of tibial tunnel increased from 82.5 to 112.7 mm2; P =.001). Expansion of the femoral tunnel was also seen; however, this change was not statistically significant (P =.18). CONCLUSIONS: The expansion after surgery occurred over time, not immediately after surgery, and was probably caused by factors other than surgical technique. The significance of tibial tunnel expansion needs to be clinically correlated with a long-term study on the effect of tunnel expansion on graft survival.

Broken poly-L-lactic acid interference screw after ligament reconstruction.

The interference screw is a reliable method used to secure tendon to bone and bone to bone in ligament reconstruction. Historically, metal interference screws have been used for this purpose in both anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction. However, several problems associated with the use of metal interference screws have led to the increasing use of bioabsorbable implants. Poly-L-lactic acid (PLLA) biodegradable interference screws have been used successfully for graft fixation in ligament reconstruction. Although adverse reactions have been reported with the use of biodegradable implants, late screw breakage is rare. To our knowledge no case exists of late screw breakage with bioabsorbable interference screws used in ligament reconstruction. We present one case in the setting of an ACL reconstruction and one with combined PCL and posterolateral corner reconstruction.

Delayed degradation of bioabsorbable meniscal fixators.

A greater understanding of the functional importance of the meniscus has prompted a more aggressive approach to conserving meniscal tissue. Multiple treatment options exist when dealing with a tear of the meniscus. As the popularity of bioabsorbable implants in the orthopaedic armamentarium grows, concern exists as to the potential associated complications. We describe a case of the failure of a bioabsorbable meniscal fixator appropriately applied to a posterior medial meniscal tear with an associated injury of the anterior cruciate ligament. Moreover, the concern of implant retention secondary to delayed degradation and resultant potential for articular cartilage damage was present.