Bone deformity in sports-related elbow osteoarthritis: influence of osteochondritis dissecans of the capitellum-a cross-sectional study.

INTRODUCTION: Sports activity can cause elbow osteoarthritis, which subsequently induces bone deformity. Osteochondritis dissecans (OCD) of the capitellum develops defects of articular surfaces and can exacerbate bone deformity. This study aimed to investigate whether OCD exacerbates deformities in sports-related elbow osteoarthritis. MATERIALS AND METHODS: Twenty-one patients who underwent bilateral computed tomography preoperatively followed by surgery for sports-related elbow osteoarthritis were included. Patients were divided into two groups according to the presence or absence of an OCD history: OCD + (n = 6) and OCD- (n = 15). Bilateral three-dimensional bone models of the humerus, ulna, and radius were created using computed tomography data, and bone deformities were extracted by subtracting healthy mirror models from the affected models using a Boolean operation. Bone deformities were divided into 22 regions in the 3 bones. The volume of the deformity was estimated by correlating the anteroposterior and lateral diameters of the OCD and by comparing the two groups. RESULTS: The anteroposterior diameter of the OCD correlated with the articular surface of the medial trochlear notch, whereas the lateral diameter correlated with the whole ulna, medial gutter of the ulna, whole radius, and lateral side of the radial head. The deformities were 2.2 times larger in the whole humerus, 1.9 times larger in the whole ulna, and 3.0 times larger in the whole radius in the OCD + group than in the OCD- group. The deformities were significantly larger in the OCD + group than in the OCD- group in the radial fossa, posterior capitellum, medial gutter, and lateral gutter in the humerus, medial gutter in the ulna, and lateral, anterior, and posterior sides of the radial head. CONCLUSION: Larger OCD exacerbated deformity in elbow OA, and the presence of OCD exacerbated deformities in sports-related elbow OA. These results demonstrate the highlight of preventing OCD progression.

Risk of nerve injury during elbow arthroscopy: ultrasonographic evaluation of preoperative patients.

BACKGROUND: To clarify the real risk of nerve injury during elbow arthroscopy, the distances of the radial and median nerves to the elbow joint were investigated using ultrasonography in patients who underwent surgery. METHODS: A total of 35 patients who underwent arthroscopic surgery of the elbow were investigated. The distances of the nerves to the capsule and bony landmarks were measured using ultrasonography. The radial nerve distances were measured at the capitellum, joint space, radial head, and radial neck levels. The median nerve distances were measured at the trochlear, joint space, and coronoid process levels. The patients were divided into 2 groups: nine patients in the hydrarthrosis (HA) group and 26 patients in the non-hydrarthrosis (non-HA) group. HA was defined as the intra-articular effusion on magnetic resonance imaging scans. RESULTS: The radial nerve ran closer to the capsule at the radial neck level in the HA group than in the non-HA group (2.0 mm vs. 5.9 mm, P < .01). In the non-HA group, the radial nerve ran closer to the radial head than in the HA group (6.3 mm vs. 8.5 mm, P = .01). The median nerve ran closer to the capsule at the trochlear level in the HA group than in the non-HA group (5.2 mm vs. 8.8 mm, P < .01). Nerves at a distance of ≤2 mm from the capsule were found in 7 patients at the radial neck of the radial nerve and in 2 patients at the trochlear region of the median nerve in the HA group. In the non-HA group, they were found in 3 patients at the radial head and in 1 patient at the joint space of the radial nerve. CONCLUSIONS: The dangerous locations for nerve injury during elbow arthroscopy vary according to hydrarthrosis, and this risk should be recognized during arthroscopic surgery.

Arthroscopic Debridement for Refractory Lateral Epicondylitis Results for Substantial Improvement in Tendinosis Scores and Good Clinical Outcomes: Qualitative and Quantitative Magnetic Resonance Imaging Analysis.

PURPOSE: To qualify and quantify the changes in magnetic resonance imaging (MRI) signals in the extensor tendons after arthroscopic debridement for lateral epicondylitis and evaluate the association between MRI findings and temporal clinical results by comparisons between recovered and unrecovered cases. METHODS: Thirty-four patients with refractory lateral epicondylitis treated with arthroscopic debridement were divided into recovered (n = 24) and unrecovered (n = 10) groups according to the Japanese Orthopaedic Association-Japan Elbow Society score. This study included any patients who underwent both the pre- and postoperative MRI and excluded patients with a previous history of any elbow surgery. Pre- and postoperative MRI findings were qualitatively categorized into 4 grades, quantified by measuring the percentage of tendinopathy area, and compared between the groups. RESULTS: Preoperatively, grading scores and percentages did not show significant differences between groups (P = .050 and .519). The respective numbers of patients with grades 1, 2, 3, and 4 were 1 (4%), 3 (13%), 10 (42%), and 10 (42%) in the recovered group; and 1 (10%), 2 (20%), 7 (70%), and 0 (0%) in the unrecovered group. The average percentages in the recovered and unrecovered groups were 42.3% (73.9 mm2/168.4 mm2); and 36.5% (50.5 mm2/131.0 mm2). However, postoperatively, they were significantly lower in the recovered group than in the unrecovered group (P = .007 and .014). The numbers and percentages in the recovered and unrecovered groups were 15 (63%), 8 (33%), 1 (4%), and 0 (0%) and 17.0% (28.6mm2/169.8mm2) and 2 (20%), 3 (30%), 5 (50%), and 0 (0%) and 30.5% (39.0 mm2/131.8 mm2). CONCLUSIONS: Qualitative and quantitative MRI is useful for evaluating the progress of tendon healing after arthroscopic debridement. In the recovered and unrecovered groups, improvement of tendinopathy area were 60% versus 16%, indicating that postoperative MRI findings reflect clinical outcomes. LEVEL OF EVIDENCE: IV, case series with subgroup analysis.

Arthroscopic Partial Excision of the Radial Head for Advanced Rheumatoid Elbow.

We treated humeroradial joint disorder in rheumatoid elbows with arthroscopic partial excision of the radial head, in which the radial head is minimally resected under arthroscopy to ensure adequate joint space and articular congruity. To examine the effect of this method, we investigated outcomes using a retrospective case series. The hypothesis of this study was that this method decreases symptoms related to the humeroradial joint and ensures articular congruity. Since 2008, we have performed arthroscopic partial excision of the radial head for 14 patients (15 rheumatoid elbows) with more than 2 years of follow-up. Surgical indications for this method were motion pain with crepitus around the humeroradial joint and joint narrowing and sclerosis on plain radiography. After synovectomy, the surface of the radial head was resected 4 to 5 mm under arthroscopy, ensuring adequate joint space and articular congruity. Osteophyte removal and anterior capsular release were performed if necessary. At the final follow-up of 54 months, pain around the humeroradial joint had resolved in all cases. Range of motion improved from 115° flexion, -39° extension, 55° pronation, and 54° supination preoperatively to 127° flexion, -27° extension, 60° pronation, and 65° supination postoperatively. The articular congruity of the humeroradial joint was well maintained at final follow-up, with the exception of 2 cases in which the space decreased after 4 years. Arthroscopic partial excision of the radial head is a promising procedure for improvement of humeroradial symptoms. This method is effective, even for advanced cases, and should be considered before total arthroplasty. [Orthopedics. 2022;45(4):209-214.].

Post-Exertional MRI Is Useful as a Tool for Diagnosis and Treatment Evaluation for Chronic Exertional Compartment Syndrome of Forearms.

Background: Chronic exertional compartment syndrome (CECS) is a rare condition, which generally occurs in athletes. Few tools are available for diagnosis and treatment evaluation. We examined pre- and post- exertional forearm magnetic resonance imaging (MRI) before and after fasciotomy since 2013. The purpose of this study was to evaluate the efficacy of pre- and post-exertional MRI before and after fasciotomy. Methods: We treated 8 forearms of 5 patients diagnosed with CECS of the forearms since 2013, including 6 forearms of 3 motocross racers, 1 forearm of 1 baseball pitcher, 1 forearm of 1 manual laborer with a history of muscle contusion. We obtained pre- and post-exertional MRI before and after fasciotomy in all cases. Pre-exertional MRI was obtained when the patient was at rest without any symptom. Post-exertional MRI was obtained after the patients repeated "grip and release" using a hand gripper with maximum effort for approximately 10 minutes until symptoms occurred. We compared MRI findings before and after fasciotomy and evaluated the correlation with clinical outcome. Results: Symptoms disappeared completely in all 3 motocross racers after fasciotomy. MRI at rest showed no abnormal high signals in all cases both before and after fasciotomy. On post-exertional MRI, T2 high area presented mainly in flexor digitorum profundus (FDP) and brachioradialis (BR) and disappeared completely after surgery. Symptoms persisted in the pitcher and the laborer after fasciotomy. T2 high area presented mainly in FDP on post-exertional MRI before fasciotomy and remained on post-exertional MRI after fasciotomy in these two patients. These intensity changes correlated strongly with their symptoms. Conclusions: We performed pre- and post-exertional MRI before and after fasciotomy. The intensity change in T2-weighted images on post-exertional MRI correlated strongly with their symptoms. Post-exertional MRI is useful for diagnosis and treatment evaluation in CECS.

Anconeus Muscle-Pedicle Bone Graft With Periosteal Coverage for Osteochondritis Dissecans of the Humeral Capitellum.

BACKGROUND: Treatment of advanced osteochondritis dissecans (OCD) of the capitellum is controversial, especially in moderate-sized lesions. PURPOSE: To establish a treatment algorithm for capitellum OCD, we tried to determine the utility of and problems associated with anconeus muscle-pedicle bone graft with periosteal coverage (ABGP) for the treatment of moderate-sized articular OCD defects of the capitellum. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: According to our protocol for elbow OCD, 16 patients (15 males, 1 female; age range, 12-17 years; mean age, 14.4 years) with a moderate-sized OCD lesion of the humeral capitellum were treated with ABGP. All patients had a full-thickness, unstable OCD lesion that was 10 to 15 mm in diameter. Clinical results and postoperative images, including radiographs and magnetic resonance imaging (MRI), were evaluated at a mean follow-up of 31 months (range, 24-66 months). RESULTS: All but 1 patient had functional improvement after the procedure and returned to previous sporting activities within 6 months. One female patient needed 1 year for functional recovery due to development of postoperative chronic regional pain syndrome (CRPS). Two patients required additional surgery, including shaving of the protruding cartilage, and they returned to their previous level of activity. Mean arc of range of flexion-extension motion was 117° preoperatively and 129° at follow-up (P = .031). Mean elbow function as assessed with the clinical rating system of Timmerman and Andrews was 136 preoperatively and 186 at follow-up (P = .00012). Bony union of the graft as demonstrated by trabecular bone bridging on radiography was obtained within 3 months in all patients. Postoperative MRI was examined for 14 patients at 6 to 12 months after the procedure; the MRIs showed near-normal articular surface integrity in 9 of the 14 patients (64%) and underlying bony structure in 10 of the 14 patients (71%). CONCLUSION: Improvement after ABGP was obtained within 6 months in all except 1 patient, who developed CRPS. Postoperative radiography and MRI revealed near-normal articular surface integrity or underlying bony structure. This procedure is useful as a surgical option for a moderate-sized articular OCD lesion in the elbow.

Medial condyle fracture of the distal humerus in an adolescent with pre-existing fishtail deformity. A case report.

Medial condyle fractures of the humerus are rare in any age group. We report a unique case of a humeral medial condyle fracture in a 15-year-old boy with posttraumatic fishtail deformity. The fracture line extended up from the top of the sharp trochlear wedge to the incomplete medial supracondylar cortical aperture. The appearance of the upward displacement and computed tomography imaging with three-dimensional reconstruction at the two different elbow positions suggested that an edge of the semilunar notch of the olecranon acted as a wedge to break and split the trochlea directly. This is the first visualized case of a wedge type injury and may provide evidence that humeral medial condyle fractures can be produced by the wedge force besides the valgus avulsion one.

Akt/mammalian target of rapamycin signaling pathway regulates neurite outgrowth in cerebellar granule neurons stimulated by methylcobalamin.

Methylcobalamin (MeCbl), a vitamin B12 analog, promotes neurite outgrowth by activating Akt in neurons. However, Akt is involved in many cellular functions, and the downstream signal of Akt that promotes neurite outgrowth in neurons in the presence of MeCbl remains obscure. Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase that regulates multiple cellular functions including neurite outgrowth. mTOR is regarded as important for the regeneration of injured nerves. In this study, we examined the relationship between MeCbl and mTOR activity and found that MeCbl increases mTOR activity via the activation of Akt and promotes neurite outgrowth in cerebellar granule neurons via the activation of mTOR.

Methylcobalamin increases Erk1/2 and Akt activities through the methylation cycle and promotes nerve regeneration in a rat sciatic nerve injury model.

Methylcobalamin is a vitamin B12 analog and is necessary for the maintenance of the nervous system. Although some previous studies have referred to the effects of methylcobalamin on neurons, the precise mechanism of this effect remains obscure. Here we show that methylcobalamin at concentrations above 100 nM promotes neurite outgrowth and neuronal survival and that these effects are mediated by the methylation cycle, a metabolic pathway involving methylation reactions. We also demonstrate that methylcobalamin increases Erk1/2 and Akt activities through the methylation cycle. In a rat sciatic nerve injury model, continuous administration of high doses of methylcobalamin improves nerve regeneration and functional recovery. Therefore, methylcobalamin may provide the basis for better treatments of nervous disorders through effective systemic or local delivery of high doses of methylcobalamin to target organs.

Interleukin-1 beta promotes sensory nerve regeneration after sciatic nerve injury.

Nerve injury brings about axonal disconnection, and thus axonal extension is one of the important steps for nerve regeneration. Expression of the pro-inflammatory cytokine interleukin-1 beta (IL-1beta) is increased at the early stage of nervous system injury, and previously IL-1beta has been reported to promote neurite outgrowth by inhibiting RhoA activity in vitro. However, the effect of IL-1beta on axonal extension in vivo has not been obvious. Now we examine whether IL-1beta takes advantages on sciatic nerve regeneration. Sciatic nerves of rats are transected and sutured, and IL-1beta or PBS is locally administered for 2 weeks. Although IL-1beta does not influence on motor functional recovery, it promotes sensory functional recovery, estimated by toe pinch test, and increases the number and the area of neurofilament-positive axons at 12 weeks compared with PBS. Moreover IL-1beta, which promotes Schwann cell proliferation and thus may inhibit myelination, does not impair remyelination, estimated by myelin basic protein. These findings suggest that IL-1beta may contribute to sensory nerve regeneration following sciatic nerve injury by promoting axonal extension.

IL-1beta promotes neurite outgrowth by deactivating RhoA via p38 MAPK pathway.

Expression of the pro-inflammatory cytokine interleukin-1 beta (IL-1beta) is increased following the nervous system injury. Generally IL-1beta induces inflammation, leading to neural degeneration, while several neuropoietic effects have also been reported. Although neurite outgrowth is an important step in nerve regeneration, whether IL-1beta takes advantages on it is unclear. Now we examine how it affects neurite outgrowth. Following sciatic nerve injury, expression of IL-1beta is increased in Schwann cells around the site of injury, peaking 1 day after injury. In dorsal root ganglion (DRG) neurons and cerebellar granule neurons (CGNs), neurite outgrowth is inhibited by the addition of myelin-associated glycoprotein (MAG), activating RhoA. IL-1beta overcomes MAG-induced neurite outgrowth inhibition, by deactivating RhoA. Intracellular signaling experiments reveal that p38 MAPK, and not nuclear factor-kappa B (NF-kappaB), mediated this effect. These findings suggest that IL-1beta may contribute to nerve regeneration by promoting neurite outgrowth following nerve injury.

Painful nonunion of fracture of the entire posterior process of the talus: a case report.

We report a 14-year-old boy in whom isolated nonunion fracture of the posterior process of the talus. He underwent surgical repair with Herbert Whipple screw fixation and plaster immobilization. Osseous union was achieved 3 months after surgery, resulting in the resolution of symptoms and complete functional recovery. To our knowledge, the present report is the first to describe a successful outcome for surgical treatment of painful nonunion of fracture of the entire posterior process of the talus.