Elbow anatomy in perspective of joint capsule and surrounding aponeuroses: a narrative review.

Background: Because of the proximity of several ligaments, aponeuroses, and capsule in the limited area of the elbow joint, the precise anatomy is difficult to understand. In the current narrative review, we focused on two anatomical perspectives: the capsular attachment and structures consisting of ligaments. Methods: Based on the previously performed studies regarding the elbow anatomy, a narrative review was prepared in terms of the capsular attachment and structures consisting of ligaments. Results: At the tip of the coronoid process, the joint capsule attaches roughly 6 mm distal to its tip with 6-12 mm length. On the lateral epicondyle of the humerus, the capsular attachment at the anterior part of the extensor carpi radialis brevis origin is narrower than the one distal to it. A single interpretation of the lateral collateral ligament is the capsulo-aponeurotic membrane, which is composed of the joint capsule intermingling with the supinator aponeurosis. The anterior bundle of the ulnar collateral ligament could be interpreted as the grossly separated collagenous structure from the tendinous complex, which is composed of the tendinous septum between the flexor digitorum superficialis and pronator teres muscle, the medial part of the brachialis muscle, and deep aponeurosis of the flexor digitorum superficialis muscle. Discussion: Based on these perspectives, ligaments could function as a "static-dynamic" stabilizer rather than a simple static one.

Radiographic and clinical comparisons between loose-fit and press-fit stems in monopolar radial head arthroplasty for comminuted radial head fractures.

PURPOSE: Few clinical studies have compared the operative outcomes between loose- and press-fit stems in radial head arthroplasty (RHA). We aimed to evaluate the radiographic and clinical results of the two radial head implant concepts. METHODS: In this retrospective multicenter study, 32 patients (24 women and 8 men) with a mean age of 63.1 years who underwent RHA for comminuted radial head fractures were reviewed between 2005 and 2021. Seventeen patients underwent RHA with a loose-fit stem (L-group), whereas the remaining fifteen patients underwent RHA with a press-fit stem (P-group). The mean follow-up period was 40.1 ± 9.9 months, with the minimum follow-up duration of 12 months. The radiographic findings were evaluated for periprosthetic osteolysis; furthermore, clinical outcomes were analyzed to measure the range of motion of the elbow. The rate of reoperations and prosthesis removal were also reviewed. RESULTS: The general characteristics of the patients were similar in the two groups. The rate of periprosthetic osteolysis was 17.6% in the L-group, whereas it was 53.3% in the P-group. The mean elbow flexions were 128° and 133° in the L- and P-groups, respectively. The mean elbow extensions were -12° and -9° in the L- and P-groups, respectively. The rate of reoperation was 23.5% in the L-group and 15.2% in the P-group. One patient in the L-group had the prosthesis removed because of surgical site infection, whereas one patient in the P-group had the prosthesis removed owing to painful loosening. CONCLUSIONS: No significant differences in the clinical outcomes and reoperation rate were observed between the two radial head implant concepts in this study. However, osteolysis occurred more frequently in the P-group. Although patients with periprosthetic osteolysis are currently asymptomatic, they should be carefully followed up for the symptoms in the long term.

Anteroinferior plating is an independent factor for decreasing symptomatic implant removal rates after plate fixation for midshaft clavicle fractures.

Objectives: The factors that significantly influence the symptomatic implant removal rates after plate fixation for midshaft clavicle fractures remain controversial. The purpose of this study was to compare the symptomatic implant removal rates between 2 different types of plating technique and to evaluate independently associated factors. Design: Retrospective cohort study. Setting: Acute care center. Patients/Participants: A total of 71 patients 16 years or older who were diagnosed with displaced midshaft clavicle fractures from April 2016 to March 2020. Intervention: Thirty-nine patients were treated with superior plating (Group SP), and the remaining 32 patients were treated with anteroinferior plating (Group AIP). Main Outcome Measurements: Symptomatic implant removal rates after plate fixation for midshaft clavicle fractures. Results: Symptomatic implant removal rates were significantly lower in Group AIP (28.1%) than in Group SP (53.8%) (P = 0.033). Multivariate analyses showed that symptomatic implant removal rates were significantly decreased by three independent factors, namely AIP (odds ratio [OR] = 0.323) (P = 0.037), greater age (45 years or older) (OR = 0.312) (P = 0.029), and high body mass index (≥25 kg/m2) (OR = 0.117) (P = 0.034). Conclusions: AIP significantly and independently decreased the symptomatic implant removal rate. Among the three explanatory factors showing significant difference, plating technique is the only factor that can be altered by medical institutions. Therefore, we recommend this technique for displaced midshaft clavicle fractures to reduce a second surgery such as symptomatic implant removal. Level of Evidence: Level 3, retrospective cohort study.

Radiation educational program significantly reduces intraoperative fluoroscopy time during locking plate fixation for distal radius fractures.

BACKGROUND: The use of C-arm fluoroscopy poses a risk of radiation exposure to the surgeons. This study aimed to examine the intraoperative fluoroscopy time of the distal radius plating before and after radiation educational program. METHODS: A total of 68 cases (48 women and 20 men; average age, 61.8 years) were reviewed between July 2017 and October 2019. All patients were treated with volar locking plate fixation for distal radius fractures. On October 2018, we had a 1-h radiation educational program for orthopedic surgeons. Intraoperative fluoroscopy time was compared between 34 cases in the preintervention group (group A) and 34 cases in the postintervention group (group B). Radiographic correction loss of the fracture was assessed by ulnar variance (UV), radial inclination (RI), and volar tilt (VT) between immediately after surgery and at the time of bone union. RESULTS: A significant difference was found in intraoperative fluoroscopy time between 329 s in group A and 123 s in group B. ΔUV between immediately after surgery and at the time of bone union was 0.6 mm in group A and 0.3 mm in group B; ΔRI was -0.3° in group A, -0.1° in group B, ΔVT is -0.4° in group A, and -0.1° in group B. No significant difference was found among them. CONCLUSIONS: After an educational program on radiation exposure, the intraoperative fluoroscopy time was significantly saved in the plating surgery for the distal radius fractures. The shortening of the intraoperative fluoroscopy time did not affect the loss of radiographic correction of the fractures.

Comparison of ceftriaxone and cefazolin as prophylactic antibiotics for surgical site infection in orthopedic upper extremity surgery: The nationwide shortage of cefazolin in March 2019.

BACKGROUND: Due to the nationwide supply shortage of cefazolin in March 2019 in Japan, ceftriaxone was used as an alternative prophylaxis antibiotic agent. This retrospective study was designed to investigate the impact of cefazolin and ceftriaxone as a prophylactic antibiotic agent for surgical site infection (SSI) in orthopedic upper extremity surgery. METHODS: We used cefazolin for antibiotic prophylaxis to prevent SSI before March 2019. Because of cefazolin shortage, ceftriaxone was used as an alternative agent in our hospital. From April 2014 to May 2021, 2493 upper extremity surgeries were reviewed. The exclusion criteria in this study were as follows: patients aged under 16 years, those with an open wound, those with infectious diseases, those who underwent trigger finger surgery, and those who underwent percutaneous pinning surgery. The incidence of deep SSI was evaluated according to the Centers for Disease Control and Prevention guidelines. RESULTS: Among the 2493 eligible cases, 1674 were included in this study. In the cefazolin group, 1140 cases were included, whereas, in the ceftriaxone group, 534 cases were included. No significant differences in the demographic data of the patients were observed between the two groups. The incidence of deep SSI was 0.08% (1/1140 cases) in the cefazolin group and 1.1% (6/534 cases) in the ceftriaxone group, with a significant difference between the two groups (odds ratio, 12.9; p = 0.005). CONCLUSIONS: This study indicated that the use of ceftriaxone instead of cefazolin after upper extremity surgery increases the risk of deep SSI.

Understanding the susceptibility to lateral condyle fracture by analyzing unaffected Baumann's angle in children with distal humeral fracture.

BACKGROUND: Previous studies have shown that posttraumatic cubitus varus deformity in children is somehow related to subsequent humeral lateral condyle fracture. Moreover, we had previously encountered an exactly similar case. In this study, we aim to understand whether there is a morphological difference between pediatric supracondylar and lateral condyle fracture of the humerus by comparing Baumann's angle of the unaffected elbow. METHODS: We conducted a retrospective evaluation of 40 cases of supracondylar fractures (36 boys, 4 girls) and 20 cases of lateral condyle fractures (16 boys, 4 girls) at a single facility between January 2014 and December 2018. The unaffected Baumann's angles and lateral capitellohumeral angles of both groups were measured by two orthopedic surgeons and analyzed using Welch's t-test. The effect size was also calculated using Cohen's d, and intraclass correlation coefficients were applied for intra-rater and inter-rater reliability. RESULTS: The average age of patients in the supracondylar fracture group was 6.78 years and that in the lateral condyle fracture group was 5.70 years. No significant differences were observed between gender and fracture type, between laterality and fracture type, and in the lateral capitellohumeral angles between the groups. Baumann's angle was significantly less in the lateral condyle fracture group (17.27° ± 4.68°) than in the supracondylar fracture group (20.28° ± 3.10°) as analyzed by Welch's t-test (p = 0.015). The effect size was 0.76. Each of the intra-rater reliabilities were 0.97 and 0.96, whereas the inter-rater reliability was 0.75. CONCLUSIONS: A significant morphological difference was found between the supracondylar fracture group and the lateral condyle fracture group. The loss of Baumann's angle which tends to occur after the healing of supracondylar fracture may increase the susceptibility to lateral condyle fracture. Orthopedic surgeons should repair and fix supracondylar fractures appropriately to avoid an ipsilateral second fracture, such as lateral condyle fracture.

Comparison of the efficacy of the tension band wiring with eyelet wire versus anatomical locking plate fixation for the treatment of displaced olecranon fractures.

BACKGROUND: This retrospective study was conducted to assess the clinical outcome and complications between tension band wiring (TBW) with eyelet wire and locking plate fixation used for the treatment of displaced olecranon fractures. METHODS: A total of 58 patients (36 males and 22 females; mean age: 63 years) were reviewed between April 2014 and September 2020. TBW with Ring Pin (RP group) was applied in 24 patients, including 15 Mayo type ⅡA and 9 Mayo type ⅡB patients. Anatomical locking plate (ALP group) was used in 34 patients, including 22 Mayo type ⅡA and 12 Mayo type ⅡB patients. Clinical outcome was evaluated using the Mayo Elbow Performance Score (MEPS), and active range of motion of the elbow and forearm and postoperative complications were reviewed. RESULTS: General characteristic of the patients and the fracture type were similar in the two groups. The mean MEPS values were 96.5 ± 7.3 in the RP group and 94.9 ± 9.4 in the ALP group. The mean elbow flexion arc was 127°±11 in the RP group. The mean elbow flexion arc was 122°±18 in the ALP group. No significant differences in clinical outcomes were observed between the two groups. Complication rates were significantly higher in the ALP group (19/34: 56%) than in the RP group (6/24: 25%). CONCLUSION: Although there were no statistically significant differences in clinical outcomes between the two groups, the ALP group had a higher proportion of any complication than the RP group.

Mid-Term Functional Outcome after Volar Locking Plate Fixation of Distal Radius Fractures in Elderly Patients.

BACKGROUND: The volar locking plate is frequently used in the fixation of unstable distal radius fractures, but despite this there is a paucity of mid to long term outcome studies. The purpose of this study was to investigate the mid-term functional outcomes of elderly patients treated with a volar locking plate for unstable distal radius fractures. METHODS: Thirty-two patients with a mean age of 74.1 (range, 65-85) years were followed for a mean of 39.1 (range, 30-81) months. Patients with follow-up periods of < 24 months were excluded from this study to investigate the mid-term clinical outcomes. The Mayo wrist score (MWS), grip strength and wrist range of motion were retrospectively reviewed at 12 months, 24 months and the latest follow-up (mean 39.1 months). Osteoarthritis status according to the system of Knirk and Jupiter was assessed at 24 months. RESULTS: Significant improvements in MWS and grip strength were observed between 12 and 24 months but not between 24 months and the final follow-up. There was no significant difference in wrist range of motion between 12 and 24 months. The MWS of 14 patients with radiographic signs of osteoarthritis was not significantly different from that of 18 patients without radiographic signs of osteoarthritis. CONCLUSIONS: Elderly patients treated with the volar locking plate showed improved MWS and grip strength postoperatively after 12 months. Improvement in grip strength was slower than range of motion.

Joint capsule attachment to the coronoid process of the ulna: an anatomic study with implications regarding the type 1 fractures of the coronoid process of the O'Driscoll classification.

BACKGROUND: The attachment of the anterior joint capsule on the ulnar coronoid process is not yet completely understood. The purpose of this study was to clarify the anatomic relationship between the anterior capsule of the elbow joint and the tip of the coronoid process. METHODS: Seventeen embalmed elbows were used for this anatomic study. The anterior capsule of the elbow joint was reflected, and the attachment of the capsule on the coronoid process was exposed. The attachment of the joint capsule on the coronoid process was macroscopically and histologically observed, its relationship to the coronoid tip was assessed, and the length of the attachment of the joint capsule was measured. RESULTS: The length of the capsule attachment at the radial side of the coronoid (11.9 mm) was greater than that at the ulnar side (6.1 mm). The bone thickness on the coronoid tip from the proximal edge of the joint capsule attachment was 1.9 mm; together, the cartilage and bone thickness was 4.7 mm. At the radial side of the coronoid, the thickness of the joint capsule at the proximal aspect of the attachment of 2 samples was 0.6 mm and 0.3 mm, and that at the tip of the coronoid was 2.6 mm and 1.7 mm, respectively. CONCLUSIONS: The anterior capsule of the elbow joint had a substantial attachment on the radial side of the coronoid process. The subtype 2 tip fractures of the O'Driscoll classification included the joint capsule attachment, joint cartilage, and subchondral bone.

Effects of lubricant and autologous bone marrow stromal cell augmentation on immobilized flexor tendon repairs.

The purpose of the study was to test a novel treatment that carbodiimide-derivatized-hyaluronic acid-lubricin (cd-HA-lubricin) combined cell-based therapy in an immobilized flexor tendon repair in a canine model. Seventy-eight flexor tendons from 39 dogs were transected. One tendon was treated with cd-HA-lubricin plus an interpositional graft of 8 × 10(5) BMSCs and GDF-5. The other tendon was repaired without treatment. After 21 day of immobilization, 19 dogs were sacrificed; the remaining 20 dogs underwent a 21-day rehabilitation protocol before euthanasia. The work of flexion, tendon gliding resistance, and adhesion score in treated tendons were significantly less than the untreated tendons (p < 0.05). The failure strength of the untreated tendons was higher than the treated tendons at 21 and 42 days (p < 0.05). However, there is no significant difference in stiffness between two groups at day 42. Histologic analysis of treated tendons showed a smooth surface and viable transplanted cells 42 days after the repair, whereas untreated tendons showed severe adhesion formation around the repair site. The combination of lubricant and cell treatment resulted in significantly improved digit function, reduced adhesion formation. This novel treatment can address the unmet needs of patients who are unable to commence an early mobilization protocol after flexor tendon repair.

A novel closed reduction with extension block and flexion block using Kirschner wires and microscrew fixation for mallet fractures.

BACKGROUND: Some patients with mallet fractures who undergo extension block pinning complain of exposed wires, which delay their return to sports and causes inconvenience while performing tasks that require the use of hands during the early postoperative period. The purpose of this retrospective study was to present and evaluate a novel surgical procedure for mallet fractures. METHODS: We treated 20 patients (14 males and six females; mean age, 38.4 years; range 17-68 years) with displaced mallet fractures involving >30 % of the articular surface using the closed reduction and microscrew fixation between January 2009 and January 2012. The distal interphalangeal joint (DIP) joint was immobilized with a splint for 1-3 weeks on an individual case basis. According to Wehbe and Schneider's classification, there were 12 type IB, six type IIB, and two type IA fractures. The mean follow-up duration was 12.6 months (range 6-31 months). RESULTS: Bone union was achieved in all patients within a mean period of 6.8 weeks, with no incidence of infection, skin necrosis, permanent nail deformity, or secondary osteoarthritis. Only two complications-temporary nail ridging in one patient and a dorsal bump caused by the screw in one patient-were observed. Minimum postoperative displacement was observed in one patient, for whom immobilization with a splint was continued for 4 weeks. Articular incongruity was <1.0 mm in four patients and 1.0-2.0 mm in two patients. Mean DIP joint extension loss was 6.5° and mean flexion was 67.8°. The surgical outcomes were excellent in seven patients, good in nine, and fair in four according to Crawford's evaluation criteria. CONCLUSION: Our novel surgical procedure combining closed reduction with extension block and flexion block using Kirschner wires and microscrew fixation produces good clinical results with relatively few complications.