Establishing minimal detectable change thresholds for the international knee documentation committee and Kujala scores at one and two years after patellofemoral joint arthroplasty.

PURPOSE: To define the minimal detectable change (MDC) for the international knee documentation committee (IKDC) and Kujala scores one and two years after patellofemoral joint arthroplasty (PFA). METHODS: A distribution-based method (one-half the standard deviation of the mean difference between postoperative and preoperative outcome scores) was applied to establish MDC thresholds among 225 patients undergoing primary PFA at a single high-volume musculoskeletal-care center. Stability of change in MDC achievement was explored by quantifying the proportion of achievement at one- and two-year postoperative timepoints. Multivariable logistic regression analysis was performed to explore the association between sociodemographic and operative features on MDC achievement. RESULTS: MDC thresholds for the Kujala score were 10.3 (71.1% achievement) and 10.6 (70.4% achievement) at one- and two years, respectively. The MDC thresholds for the IKDC score were 11.2 (78.1% achievement) and 12.3 (69.0% achievement) at one- and two years, respectively. Predictors of achieving the MDC for the Kujala and IKDC scores at both time points were lower preoperative Kujala and IKDC scores, respectively. Preoperative thresholds of ≤ 24.1 and 7.6 for the Kujala and IKDC scores, respectively, were associated with a 90% MDC achievement probability. When preoperative thresholds approached 64.3 and 48.3 for the Kujala and IKDC, respectively, MDC achievement probability reduced to 50%. CONCLUSION: The MDC thresholds for the Kujala and IKDC scores two years after PFA were 10.6 and 12.3, respectively. Clinically significant health status changes were maintained overall, with a slight decrease in achievement rates between one and two years. MDC achievement was associated with disability at presentation, and several probability-based preoperative thresholds were defined. These findings may assist knee surgeons with patient selection and the decision to proceed with PFA by better understanding the patient-specific propensity for MDC achievement. LEVEL OF EVIDENCE: IV, retrospective case series.

Comparison of tibial inlay versus transtibial techniques for isolated posterior cruciate ligament reconstruction: minimum 2-year follow-up.

PURPOSE: Surgical treatment of isolated posterior cruciate ligament (PCL) injuries is controversial. The purpose of this retrospective study was to evaluate the surgical outcomes of PCL reconstruction. Two techniques were compared, the traditional endoscopic and the more recent tibial inlay, to determine if the inlay technique yielded more stable reconstructions. TYPE OF STUDY: Retrospective study of surgical outcomes. METHODS: Between 1980 and 1997 [corrected], 29 patients underwent surgery for isolated PCL injuries at our institution. Two patients underwent primary repair, 4 underwent primary repair with semitendinosus-gracilis augmentation, and 1 had a tibial inlay with a double femoral tunnel, and these patients were excluded from this study. Two patients were lost to follow-up, leaving 20 patients who were evaluated at a mean follow-up of 5.7 years (range, 2 to 15 years). The average age at surgery was 29 years (range, 17 to 49 years). The primary indication for surgery was instability (95%). The surgical procedures included 13 traditional endoscopic transtibial PCL reconstructions (9 bone-patellar tendon-bone [BPTB] autograft, 2 BPTB allograft, and 2 allograft Achilles tendon) and 7 tibial inlay (all BPTB, 5 allograft and 2 autograft). Each patient was evaluated using the Tegner, Lysholm, and American Academy of Orthopaedic Surgeons (AAOS) knee-rating scales, physical examination, corrected KT-1000 arthrometry, functional testing, and radiographs. Statistical analysis was performed using the Fisher exact t test, Wilcoxon signed-ranks test, and Mann-Whitney test. RESULTS: Overall, 90% pf patients were satisfied with their surgery. The postoperative posterior drawer test result improved in 4 of 7 (57%) in the inlay group, and in 5 of 13 (38%) in the endoscopic group. The mean corrected KT-1000 measurement was 5.7 mm overall, 5.5 mm (inlay) and 5.9 mm (endoscopic). The mean preoperative Tegner score was 6.86 (inlay) and 6.92 (endoscopic). The mean postoperative Tegner score was 6.00 for both groups. The mean Lysholm score was 76 (inlay) and 82 (endoscopic), and the AAOS knee score was 77 (inlay) and 90 (endoscopic). There was a trend toward increased radiographic progression of Fairbanks changes in the medial and patellofemoral compartments in the endoscopic group, but the numbers did not reach statistical significance (P = .057). CONCLUSIONS: When comparing the traditional endoscopic reconstructions with the tibial inlay technique, there were no significant differences in posterior drawer testing, KT-1000, functional testing, or Lysholm, Tegner, and AAOS knee scores at a minimum 2 year follow-up. CLINICAL RELEVANCE: The results of this study indicate that neither method (transtibial or inlay) of PCL reconstruction consistently restores anteroposterior stability to its original state when using a single-bundle femoral attachment site.

Arthritis and osteotomies in anterior cruciate ligament reconstruction.

Unfortunately, young patients with active life-styles who present with an ACL-deficient knee and early evidence of arthritis remain a very difficult population to treat. Arthroscopic ACL reconstruction is a proven and effective way to treat patients with anterior knee instability [2]. In addition, numerous authors have demonstrated that knee osteotomies are effective in addressing isolated medial or lateral compartment degenerative disease, even in the presence of anterior knee instability [7, 9, 22, 43]. A comprehensive evaluation of pain, alignment, and stability are necessary in order to formulate the best treatment plan for each patient. Patients with combined chronic instability secondary to ACL insufficiency and unicompartmental arthritis will generally benefit from arthroscopic debridement, ACL reconstruction, knee osteotomy, or any combination thereof. Expectations of patients should be managed according to their underlying pathology, and this is a critical component for the success of the surgery. Most patients will get some degree of symptomatic relief and functional improvement. A return to competitive or high-level sports is an unrealistic goal, however, and should be discouraged.