Background: Historically, total hip arthroplasty (THA) performed in patients ≤20 years old has been associated with poor survivorship because of bearing-surface wear with conventional polyethylene, acetabular loosening with cemented sockets, and liner fracture in ceramic-on-ceramic (CoC) THA. For this population, there is a paucity of data regarding outcomes of THAs performed with use of modern implants and bearing surfaces. The purpose of the present study was to examine the mid- to long-term outcomes of modern THA in patients ≤20 years old. Methods: Utilizing a single-institution, prospectively collected total joint registry, we retrospectively identified 91 primary THAs performed in 78 patients ≤20 years old from 1998 to 2016. The average patient age was 17 years (range, 11 to 20 years), and the average body mass index was 26 kg/m2 (range, 16 to 49 kg/m2). Forty-eight THAs (53%) were performed in male patients, and 47 (52%) were performed on the right hip. Bearing surfaces included CoC (53 THAs, 58%), metal-on-highly cross-linked polyethylene (MoP; 28 THAs, 31%), and ceramic-on-highly cross-linked polyethylene (CoP; 10 THAs, 11%). Outcome measures included reoperations, revisions, complications, clinical outcome scores, and bearing-surface wear. Results: At an average follow-up of 8 years (range, 2 to 18 years), the average modified Harris hip score was 92 (range, 54 to 100), and 95% of patients reported feeling “much better” following the surgical procedure. Survivorship at 2, 5, and 10 years postoperatively was 96.7%, 96.7%, and 95.0% for reoperation; 98.9%, 98.9%, and 97.2% for revision; and 91.2%, 91.2%, and 89.5% for complications, respectively. The most common complications were instability (3 THAs, 3%), aseptic acetabular loosening (2 THAs, 2%), and postoperative foot drop (2 THAs, 2%). Linear articular wear averaged 0.019 mm/yr. There were no correlations between age, sex, body mass index, bearing surface, femoral head size, use of cement, or operative time and survivorship from complications, reoperations, or revisions. There were no differences in linear wear among CoC, CoP, and MoP bearing surfaces. Conclusions: In patients ≤20 years old, THAs performed with use of modern implants exhibit excellent clinical outcome scores and survivorship at mid- to long-term follow-up. CoC, CoP, and MoP bearing surfaces have similar survivorship, clinical outcomes, and bearing-surface wear in this population. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background: The hook test is a sensitive and specific tool that has been previously described for diagnosing distal biceps tendon ruptures in an efficient, cost-effective manner. However, its application in postoperative evaluations after surgical repair of distal biceps tendon ruptures is not documented. Hypothesis/Purpose: We hypothesized that the hook test result returns to normal at some point postoperatively after distal biceps repair. This information could be used in decision making during follow-up examinations with both normal and abnormal findings. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: We retrospectively reviewed records of distal biceps repair. Between July 1, 2003, and July 1, 2016, a total of 56 patients underwent distal biceps repair and also had clear documentation of the results of the hook test during the postoperative period. Hook test results consisted of “intact,” “abnormal,” or “absent.” The timing of the return to a normal hook test result was recorded. Results: Overall, 51 of 57 (89%) repairs were documented to have the hook test result return to “intact.” The test result returned to intact by a mean of 10 weeks after surgery (range, 2 weeks to 15 months). The biceps tendon was intact according to the hook test at the 4-month follow-up in 45 of the 51 patients (88%) in whom it ultimately returned. The hook test result was abnormal in 5 repairs in 5 patients with only a short-term follow-up, ranging from 2 to 7 weeks postoperatively. One patient with an abnormal hook test result at 2 weeks postoperatively underwent revision and was confirmed to have a partial tear of the biceps insertion. His hook test result returned to intact 3 months after revision repair. Conclusion: The hook test result returns to normal in patients who undergo distal biceps repair in the primary and revision settings with adequate follow-up. The vast majority of patients have a normal hook test result by 4 months postoperatively. An abnormal hook test result at 4 months postoperatively may indicate a failed repair and should prompt further investigation.

Level IV, therapeutic study.