Particulated Costal Hyaline Cartilage Allograft With Subchondral Drilling Improves Joint Space Width and Second-Look Macroscopic Articular Cartilage Scores Compared With Subchondral Drilling Alone in Medial Open-Wedge High Tibial Osteotomy.

PURPOSE: To compare the articular cartilage regeneration based on second-look arthroscopy in patients who underwent medial open-wedge high tibial osteotomy (MOWHTO) combined with particulated costal hyaline cartilage allograft (PCHCA) implantation with those who underwent MOWHTO and subchondral drilling (SD). Moreover, we compared the clinical and radiographic outcomes between the groups. METHODS: From January 2014 to November 2020, patients with full-thickness cartilage defect on the medial femoral condyle who underwent MOWHTO combined with PCHCA (group A) or SD (group B) were reviewed. Fifty-one knees were matched after propensity score matching. The status of regenerated cartilage was classified according to the International Cartilage Repair Society-Cartilage Repair Assessment (ICRS-CRA) grading system and Koshino staging system, based on second-look arthroscopic findings. Clinically, the Knee Injury and Osteoarthritis Outcome Score, the Western Ontario and McMaster Universities Osteoarthritis Index, and range of motion were compared. Radiographically, we compared the differences in the minimum joint space width (JSW) and change in JSW. RESULTS: The average age was 55.5 years (range, 42-64 years), and the average follow-up period was 27.1 months (range, 24-48 months). Group A showed a significantly better cartilage status than group B based on the ICRS-CRA grading system and Koshino staging system (P < .001 and <.001, respectively). There were no significant differences in clinical and radiographic outcomes between groups. In group A, the minimum JSW at the last follow-up was significantly increased than that before surgery (P = .013), and a significantly greater increase in JSW was observed in group A (P = .025). CONCLUSIONS: When performed with MOWHTO, the combination of SD and PCHCA was associated with superior articular cartilage regeneration on the ICRS-CRA grading and Koshino staging on second-look arthroscopy performed at a minimum of 2 years follow-up than SD alone. However, there was no difference in clinical outcomes. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Bone Hook Reduction Technique Combined with Lateral Parapatellar Arthrotomy for Periprosthetic Distal Femoral Fractures Following Total Knee Arthroplasty: A Technical Note.

OBJECTIVE: To report a bone hook reduction technique combined with lateral parapatellar arthrotomy for periprosthetic distal femoral fractures following total knee arthroplasty (TKA). METHODS: From April 2012 to June 2018, a total of 31 knees who underwent this technique for the treatment of periprosthetic distal femoral fractures following TKA were retrospectively reviewed. Through a lateral parapatellar arthrotomy, the vastus lateralis fascia was dissected from the muscle belly to allow anteromedial mobilization of the muscles. With direct visualization of the posteriorly angulated distal fragment, a bone hook was placed on the anterior flange of the femoral component. The hook was then elevated to correct the posteriorly angulated and shortened distal fragment. The coronal and sagittal alignments of the distal segment with the femoral shaft were confirmed using fluoroscopic images, and internal fixation was performed using an anatomically pre-contoured lateral locked plate. Once the overall length and sagittal plane alignment were restored, the plate was inserted via the previous articular approach. The plate was centered on the femur using anteroposterior and lateral fluoroscopy and then fixed. RESULTS: A total of 28 patients underwent internal fixation using the bone hook reduction technique combined with lateral parapatellar arthrotomy for the treatment of periprosthetic distal femoral fractures following TKA. The average age at operation was 70.9 years (range, 62-83 years), and the average follow-up period was 17.5 months (range, 12-48.5 months). Fractures were classified as Su type I (13/28 [46.4%]), type II (11/28 [39.3%]), and type III (4/28 [14.3%]). Bone union was confirmed radiographically in all patients. CONCLUSION: The bone hook reduction technique is a simple and effective method to reduce the distal fragment in periprosthetic distal femoral fractures following TKA.