笹沼 秀幸

BACKGROUND: This study aimed to morphologically and histologically examine whether pig is useful as models for rotator cuff tear (RCT). METHODS: The morphology of the scapula and humerus bones was evaluated by taking X-ray and three-dimensional computed tomography (3D CT) scans of the right shoulders of five female pigs (age: 4 months). The rotator cuff (RC) footprint at the humeral insertion of these was observed and its shape was measured. Next, they underwent general anesthesia and an acute rotator cuff tear/rotator cuff repair (RCT/RCR) model was created using a deltoid split approach. Four weeks after surgery, the animals were euthanized, the shoulder joints were harvested, and the repaired RC was evaluated by hematoxylin and eosin staining and toluidine blue staining. RESULTS: The scapula of the pig had a vestigial acromion, in contrast to that in humans. The supraspinatus and infraspinatus tendons were connected so as to overlap each other and attached to the postero-superior part of the greater tuberosity. These tendons were located extra-articularly, separate from the joint capsule. The average antero-posterior length of the foot print was 17.4 ± 0.7 mm on the medial margin and 19.1 ± 2.2 mm on the lateral margin. The maximum medial-to-lateral width of it was 5.1 ± 0.5 mm. In all RCT/RCR models at 4 weeks after surgery, the repaired RC compound tendon was visually confirmed to be continuous with the footprint. Histologically, it was confirmed that regeneration of the four-layer structure of the bone-tendon junction had occurred. CONCLUSION: Porcine supraspinatus and infraspinatus attachment to the greater tuberosity have a structure similar to that of sheep and dogs, which is advantageous for creating the RCT/RCR model. It might be used for future in vivo studies of shoulder joint diseases. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: Pigs could potentially serve as a viable model for rotator cuff tears.

A 72-year-old female patient with a fixed valgus knee deformity due to a Schatzker type V tibial plateau fracture treated with bilateral locking plates 8 years ago was admitted to our clinic with complaints of chronic pain and knee instability when walking. Radiographs revealed Kellgren-Lawrence Classification grade 4 knee osteoarthritis and 20.5° of valgus knee deformity. She was treated with three-dimensional templating and proximal lateral tibial fitting patient-specific instrumentation-assisted mechanically aligned posterior sacrificing total knee arthroplasty with minimal removal of the retained hardware for the internal fixation of the tibial plateau fracture via a lateral approach, resulting in a favorable clinical outcome. The use of proximal lateral tibial fitting patient-specific instrumentation in fixed valgus complex primary total knee arthroplasty for patients with retaining hardware for internal fixation to treat tibial plateau fractures is considered a treatment option to decrease surgical invasion.

BACKGROUND: Osteochondral autograft transplant (OAT), a surgical treatment for capitellar osteochondritis dissecans (OCD), has favorable rates of elbow recovery and return to sports in adolescents. However, few reports have investigated how long patients continue to play baseball after OAT and their satisfaction with their treatment outcome. PURPOSE: To evaluate the rate of boys who played baseball and received OAT for OCD in junior high school or earlier (age <15 years) and continued to play baseball in high school and the players' satisfaction with their elbow function during play. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 32 elbows of boys who played baseball and received OAT at age ≤15 years (mean, 14.1 years) were examined and divided into pitcher (n = 11) and nonpitcher (n = 21) groups according to their player position before surgery. The clinical Timmerman-Andrews score at the end of their high school baseball, participation percentage of players who continued to play baseball, and satisfaction level during play (on a scale of 0-10 during pitching and batting and in a 4-choice format) were compared between the 2 groups. RESULTS: The Timmerman-Andrews scores significantly improved after surgery in both groups, with no significant difference between the groups. Of the 32 players, 30 (93.8%) continued to play baseball throughout high school, including all players in the pitcher group and 19 (90.5%) of those in the nonpitcher group. The percentage of players who continued to pitch was 55.6% (6/11) in the pitcher group. Satisfaction with elbow joint function at the time of pitching was significantly lower in the pitcher group. Further, 5 players reported being "a little unsatisfied" because of elbow pain during pitching. All of the players indicated satisfaction with elbow function during batting. CONCLUSION: The percentage of players who received OAT for OCD in junior high school and continued to play baseball in high school was favorable. However, satisfaction with elbow function during throwing was lower in pitchers than in nonpitchers. CLINICAL RELEVANCE: Before surgery, consent should be obtained from patients who are pitchers after it is explained that satisfaction with elbow joint function during pitching could be decreased after OAT.