Clinical significance of upper arm motor nerve conduction velocity in cubital tunnel syndrome

Background

Retrograde denervation occurs in severe entrapment neuropathy. This study aimed to investigate changes in motor nerve conduction velocity (MNCV) at the upper arm, specifically proximal to the elbow, in cubital tunnel syndrome (CuTS) and to correlate these changes with preoperative severity and postoperative outcomes.

Methods

We retrospectively reviewed 95 elbows with 81 patients with CuTS for preoperative severity, and then 67 elbows with 60 of these patients who underwent anterior subcutaneous transposition surgery for postoperative outcome, classified into favorable and unfavorable groups according to Messina grade.

Results

The reduction of upper arm MNCV was correlated with aging, decreased compound muscle action potentials of abductor digiti minimi muscle, loss of sensory nerve action potentials, and modified McGowan grade. Postoperative assessment revealed lower MNCV values in the "unfavorable" group compared to the "favorable" group at 1 month, 6 months, and the last follow up. At each time point, the optimal cut-off value of upper arm MNCV for predicting postoperative outcomes was 54.1 m/s.

Discussion

Upper arm MNCV might be a useful predictor of poor surgical outcome. Ulnar nerve MNCV at the upper arm should be measured alongside routine assessment of MNCV at the elbow and forearm, especially in clinically severe cases considering surgery.

Structural and Functional Alterations of the Deltoid Muscle After Arthroscopic Rotator Cuff Repair: A 2-Year Longitudinal Observation Study

Background

Deltoid muscle detachment and atrophy have been reported to occur after shoulder surgery.

Purpose

To investigate the 2-year changes in deltoid muscle structure and function after arthroscopic rotator cuff repair (ARCR) using magnetic resonance imaging (MRI) and electrophysical examination.

Study Design

Case series; Level of evidence, 4.

Methods

A total of 72 patients (72 shoulders) who underwent ARCR between 2015 and 2020 were enrolled. Whole deltoid muscle volume and regional (anterior, lateral, and posterior) muscle thicknesses were determined on T2-weighted MRI scans of both shoulders taken preoperatively and at 1, 3, 6, 12, and 24 months postoperatively, and their correlations with compound muscle action potentials (CMAPs), shoulder abduction muscle strength, and Constant scores were investigated. Comparison between groups was performed using paired or Student t tests, and the relationship between deltoid muscle volume and various factors was determined using Pearson correlation analysis.

Results

The volume of the deltoid muscle on the affected side decreased from 44,369 ± 12,371 mm3 preoperatively to 38,139 ± 10,615 mm3 at 1 month postoperatively (P < .05), representing a 14% decrease. The deltoid muscle volume of the contralateral side also significantly decreased during the same time frame, from 43,278 ± 12,248 to 40,273 ± 11,464 mm3 (P < .05), representing a 7% decrease at 1 month postoperatively. Subsequently, the deltoid muscle volume on both sides recovered to preoperative levels at 12 months and was maintained at 24 months. Only the thickness of the anterior part of the deltoid was markedly decreased, from 13.9 ± 3.7 mm preoperatively to 12.0 ± 3.2 mm at 1 month postoperatively (P < .05), representing a 14% reduction. The CMAP amplitude showed a significant decrease at 1 month postoperatively; however, no significant difference was observed after 12 months when compared with the preoperative values or the values on the contralateral side. Positive correlations were found between deltoid muscle volume and CMAP amplitude at 24 months as well as between deltoid muscle volume and shoulder abduction muscle strength (R 2 = 0.698; P < .05) and Constant score (R 2 = 0.133; P < .05).

Conclusion

Our study demonstrated that the early structural and functional decline of the deltoid muscle after ARCR was fully recovered within 1 year, confirming that this procedure does not negatively affect the deltoid muscle.

Novel subtype of coxitis knee associated with acetabular dysplasia of the hip: a case series

BACKGROUND

Multiple joint arthritis patterns require a comprehensive understanding to optimize patient management. This study aimed to present a patient cohort that deviated from known definitions of coxitis knee (CK), identifying and characterizing this atypical group.

METHODS

Patients undergoing both total hip arthroplasty and total knee arthroplasty between January 2008 and December 2018 were retrospectively reviewed. The patients were classified into a typical coxitis knee group (classic, long leg arthropathy, and windswept deformity) and an atypical coxitis knee group. Leg-length discrepancy, body mass index (BMI), and radiographic parameters of the groups were compared and analyzed.

RESULTS

A total of 31 patients were allocated to the typical coxitis knee group (n = 10), and atypical coxitis knee group (n = 21). In the atypical group, 27 hips were involved, of which 21 had acetabular dysplasia, 5 exhibited subchondral insufficiency fracture-like changes, and only 1 had classic osteoarthritis. Among the 27 knees undergoing total knee arthroplasty, 26 showed varus alignment, 1 was within the normal range, and none was valgus. Acetabular dysplasia involved ipsilateral (n = 1), contralateral (n = 14), and bilateral (n = 6) hips, showing atypical coxitis knee. Patients with acetabular dysplasia were more likely to exhibit atypical CK.

CONCLUSION

Most patients in the cohort displayed acetabular dysplasia and contralateral varus knees, constituting a pattern referred to as acetabular dysplasia-associated gonarthritis. Identifying this novel subtype may have important clinical implications for regions with high risk factors, where acetabular dysplasia and constitutional genu varum are prevalent.

Reference intervals and sources of variation of pressure pain threshold for quantitative sensory testing in a Japanese population

Quantitative sensory testing (QST) is useful when analysing musculoskeletal pain disorders. A handheld algometer is most commonly used for pressure pain threshold (PPT) tests. However, reference intervals for PPTs are not elucidated. We assessed reference intervals of PPTs for QST in 158 healthy adult Japanese with no history of musculoskeletal or neurological problems. A handheld algometer was used to record PPT at five different assessment sites on the body: lumbar paravertebral muscle, musculus gluteus maximus, quadriceps, tibialis anterior muscle, and anterior talofibular ligament. Multiple regression analysis was performed to explore sources of variation of PPT according to sex, age, body mass index, UCLA Activity Level Rating, and Tegner Activity Score. Reference intervals were determined parametrically by Gaussian transformation of PPT values using the two-parameter Box-Cox formula. Results of multiple regression analysis revealed that age was significantly associated with PPT of lumbar paravertebral muscle and musculus gluteus maximus. In females, body mass index showed significant positive correlation with PPT of anterior talofibular ligament, and UCLA Activity Level Rating also showed significant positive association with tibialis anterior muscle and anterior talofibular ligament. Site-specific reference intervals of PPTs for Japanese are of practical relevance in fields of pain research using a handheld algometer.

Neutrophil-, Monocyte- and Platelet-to-Lymphocyte Ratios, and Absolute Lymphocyte Count for Diagnosis of Malignant Soft-tissue Tumors

BACKGROUND/AIM

Soft-tissue tumors are difficult to differentiate as benign or malignant. Immune markers, such as the neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), platelet-lymphocyte ratio (PLR), and absolute lymphocyte count (ALC) in serum, have been reported to be useful in the diagnosis and predicting prognosis of several malignancies. We investigated the diagnostic value of these immune markers in differentiating soft-tissue tumors.

PATIENTS AND METHODS

A total of 692 patients who underwent biopsy or surgery of soft-tissue tumors were included and divided into benign tumor, low-grade malignancy, or high-grade malignancy groups. Immune markers were calculated from the preoperative blood tests and compared between the groups. A receiver operating curve (ROC) analysis was conducted between the benign disease group and a combination of the groups with malignancy to determine which immune marker had the most diagnostic value.

RESULTS

NLR and MLR were significantly different between the three groups with benign disease having the lowest value and high-grade malignancies the highest. Benign disease was also associated with lower PLR and higher ALC. There was no difference between the low- and high-grade malignancies in PLR and ALC. From the ROC analysis, NLR had the highest area under the curve (AUC) value of 0.773 out of the four markers. When limited to small tumors (≤30 mm), NLR had the highest AUC value of 0.729.

CONCLUSION

The NLR showed the highest diagnostic value, although the diagnostic ability was not adequately high to differentiate benign and malignant soft-tissue tumors alone. NLR may serve as diagnostic support in combination with clinical history, physical findings, and tumor-imaging results.

Novel nano-hydroxyapatite coating of additively manufactured three-dimensional porous implants improves bone ingrowth and initial fixation

Electron beam melting (EBM) has been used to fabricate three-dimensional (3D) porous Ti-6Al-4V surfaces for acetabular cups in total hip arthroplasty. However, there are radiographic concerns regarding poor implant fixation and bone ingrowth around electron beam melted (EBMed) 3D porous cups. We hypothesize that nano-hydroxyapatite (nHA) coating can promote bone ingrowth and thus decrease the occurrence of radiolucent lines around EBMed 3D porous cups. This study aimed to investigate the effect of a novel nHA coating on the biological performance of EBMed 3D porous implants in a beagle transcortical model. Low-porosity (control) and high-porosity 3D porous Ti-6Al-4V implants were manufactured using EBM. Half of the high-porosity implants were coated with nHA without clogging the 3D pores. Implants were inserted into the femoral diaphysis of the beagles. The beagles were euthanized at 4, 8, and 12 weeks postoperatively, and push-out testing was performed. Bone ingrowth was evaluated by histological analysis. Although the increase in porosity alone had no effect on biological behavior, the addition of nHA to high-porosity 3D implants significantly improved early bone fixation and bone ingrowth into the deep region of porous structures compared to low-porosity implants. This is the first report of a novel nHA coating that improved bone ingrowth into the deeper regions of 3D porous implants, which can prevent the occurrence of radiolucent lines around EBMed 3D porous cups.

Optimal intraoperative medial joint gap in extension to prevent flexion contracture following total knee arthroplasty using modified gap balancing technique

Background

Primary aim to identify the ideal medial joint gap in extension needed to prevent post-operative flexion contracture following total knee arthroplasty (TKA) in varus osteoarthritic knees by the modified gap balancing technique. A secondary aim was to analyze multiple factors that influence knee extension in TKA by modified gap balancing.

Methods

This is a prospective cohort study of 150 patients diagnosed with osteoarthritic varus knee who underwent TKA using the modified gap balancing technique. Operative and clinical records were assessed to determine factors including age, BMI (Body mass index), pre-operative extension angle and the medial extension laxity. Patients were followed for 6-months post-operatively and reviewed for knee extension angle.

Results

Six months final follow-up information was available for 148 patients with an average age of 75.5 years. Pre-operative knee extension and BMI were significantly associated with post-operative knee extension. Post-operative flexion contracture of ≧ 100 was not seen in any of 34 patients with a medial extension laxity ≧ 0 mm who had no pre-existing flexion contracture, and in 1/9 (11.1%) patients with a medial extension laxity ≧ 1 mm who had pre-existing flexion contracture.

Conclusions

Pre-operative extension angle and BMI significantly influence the post-operative knee extension angle in TKA using the modified gap balancing technique. A medial extension laxity of at least 1 mm is ideally needed to prevent post-operative flexion contracture in patients with a pre-existing contracture ≧ 100.

Level of evidence

Level II; Prospective cohort study.

Resurfacing Egg-shell Patellar Defect in a Single-staged Primary total Knee Arthroplasty - A Case Report

Introduction

Patellofemoral biomechanics are a very critical factor for patient satisfaction after total knee arthroplasty. Patellar defects in a primary total knee arthroplasty are rare. We present a rare case of valgus deformed knee with an eroded egg-shell like patella managed with primary knee arthroplasty.

Case Report

A 58-year-old female with bilateral knee pain for 35-years presented to us with a bilateral valgus knee. The knee range of movement was restricted more on the left side and severely restricting her activities of daily living. She had an egg-shell like eroded patellar defect in an osteoarthritic knee for which, she underwent primary total knee arthroplasty and patellar resurfacing with autologous bone graft harvested from the tibial cut bone.

Conclusion

We have presented a rare case of a combination of patellar defect in an Osteoarthritic knee which was managed by modified gapbalancing technique of TKA with a novel method of patellar resurfacing in a single stage with good functional results at 1-year postoperatively. This case improves our understanding of the management of such complex scenarios and, more importantly raises the questions our understanding and need of classification of such patellar defects in a primary arthritic knee.

Current Concept of Quantitative Sensory Testing and Pressure Pain Threshold in Neck/Shoulder and Low Back Pain

In recent years, several published articles have shown that quantitative sensory testing (QST) and pressure pain threshold (PPT) are useful in the analysis of neck/shoulder and low back pain. A valid reference for normal PPT values might be helpful for the clinical diagnosis of abnormal tenderness or muscle pain. However, there have been no reliable references for PPT values of neck/shoulder and back pain because the data vary depending on the devices used, the measurement units, and the area examined. In this article, we review previously published PPT articles on neck/shoulder and low back pain, discuss the measurement properties of PPT, and summarize the current data on PPT values in patients with chronic pain and healthy volunteers. We also reveal previous issues related to PPT evaluation and discuss the future of PPT assessment for widespread use in general clinics. We outline QST and PPT measurements and what kinds of perceptions can be quantified with the PPT. Ninety-seven articles were selected in the present review, in which we focused on the normative values and abnormal values in volunteers/patients with neck/shoulder and low back pain. We conducted our search of articles using PubMed and Medline, a medical database. We used a combination of “Pressure pain threshold” and “Neck shoulder pain” or “Back pain” as search terms and searched articles from 1 January 2000 to 1 June 2022. From the data extracted, we revealed the PPT values in healthy control subjects and patients with neck/shoulder and low back pain. This database could serve as a benchmark for future research with pressure algometers for the wide use of PPT assessment in clinics.

Significant reduction of patellar height affected lower clinical outcomes and knee flexion over five-year follow-up after total knee arthroplasty

Aims

This study aimed to investigate the relationship between changes in patellar height and clinical outcomes at a mean follow-up of 7.7 years (5 to 10) after fixed-bearing posterior-stabilized total knee arthroplasty (PS-TKA).

Methods

We retrospectively evaluated knee radiographs of 165 knees, which underwent fixed-bearing PS-TKA with patella resurfacing. The incidence of patella baja and changes in patellar height over a minimum of five years of follow-up were determined using Insall-Salvati ratio (ISR) measurement. We examined whether patella baja (ISR < 0.8) at final follow-up affected clinical outcomes, knee joint range of motion (ROM), and Knee Society Score (KSS). We also assessed inter- and intrarater reliability of ISR measurements and focused on the relationship between patellar height reduction beyond measurement error and clinical outcomes.

Results

The ISR gradually decreased over five years after TKA, and finally 33 patients (20.0%) had patella baja. Patella baja at the final follow-up was not related to passive knee ROM or KSS. Interestingly, when we divided into two groups - patella baja and patella normal-alta (ISR ≥ 0.8) - the patella baja group already had a lower patellar height before surgery, compared with the patella normal-alta group. The ISR measurement error in this study was 0.17. Both passive knee flexion and KSS were significantly decreased in the group with a decrease in ISR of ≥ 0.17 at final follow-up.

Conclusion

Patellar height gradually decreased over five years of follow-up after TKA. The reduction in patellar height beyond measurement error following TKA was associated with lower clinical outcomes.

Cite this article: Bone Jt Open 2021;2(12):1075–1081.

Effects of sclerostin antibody on bone healing

Promoting bone healing after a fracture has been a frequent subject of research. Recently, sclerostin antibody (Scl-Ab) has been introduced as a new anabolic agent for the treatment of osteoporosis. Scl-Ab activates the canonical Wnt (cWnt)-β-catenin pathway, leading to an increase in bone formation and decrease in bone resorption. Because of its rich osteogenic effects, preclinically, Scl-Ab has shown positive effects on bone healing in rodent models; researchers have reported an increase in bone mass, mechanical strength, histological bone formation, total mineralized callus volume, bone mineral density, neovascularization, proliferating cell nuclear antigen score, and bone morphogenic protein expression at the fracture site after Scl-Ab administration. In addition, in a rat critical-size femoral-defect model, the Scl-Ab-treated group demonstrated a higher bone healing rate. On the other hand, two clinical reports have researched Scl-Ab in bone healing and failed to show positive effects in the femur and tibia. This review discusses why Scl-Ab appears to be effective in animal models of fracture healing and not in clinical cases.

Overexpressed osteoactivin reduced osteoclastic callus resorption during distraction osteogenesis in mice

Distraction osteogenesis is a widely used surgical technique to treat bone deformity and shortening. Several biological treatments have been studied to enhance bone formation during distraction osteogenesis in animals. However, role of osteoactivin in the osseous tissues during distraction osteogenesis remains poorly understood. In this animal experimental study, we investigated the spatiotemporal expression of osteoactivin by immunohistochemistry and real-time PCR using a mouse model for tibial lengthening. Furthermore, to address the role of osteoactivin in bone lengthening, we subjected the osteoactivin-transgenic mice to distraction osteogenesis model. During the lag phase, the fibroblast-like cells (possible progenitors of the osteoblasts or chondrocytes), which mainly express osteoactivin, were infiltrated into the osteotomy site. Osteoactivin was ubiquitously expressed in the lengthened segment during the distraction and consolidation phases. Consistent with the immunohistochemical analysis, the levels of the osteoactivin transcripts in the tibias were significantly increased throughout the distraction osteogenesis process. The bone mineral content in the osteoactivin-transgenic mice calculated using peripheral quantitative computed tomography was also significantly increased at the remodeling zone. The histomorphometric analysis revealed that newly formed callus resorption in the remodeling zone was significantly reduced but bone formation was not altered in the osteoactivin-transgenic mice. We conclude that osteoactivin functions as an inhibitor of callus resorption during the consolidation phase of distraction osteogenesis.

Greater Trochanteric Fracture with Lesser Trochanter Extension: A Report of 2 Cases and CT-Based Finite Element Analysis

CASE

Two patients (aged 71 and 82 years) presented with a greater trochanteric fracture with lesser trochanter extension. These cases were successfully treated by prophylactic osteosynthesis to prevent secondary intertrochanteric/cervical fracture and to facilitate an early return to daily life. We also clarified the mechanical strength of the area that escaped bone fracture using the patient-specific computed tomography-based finite element method (CT/FEM).

CONCLUSIONS

The present fractured femurs were shown to halve the axial compression strength and had only one-sixth torsional strength in patient-specific CT/FEM. These data support prophylactic surgery to prevent the secondary fractures because of this injury.

The AO trauma CPP bone infection registry: Epidemiology and outcomes of Staphylococcus aureus bone infection

Bone infection represents a serious complication of orthopedic surgery and Staphylococcus aureus is the most common pathogen. To improve the understanding of host-pathogen interaction, we developed a biospecimen registry (AO Trauma CPP Bone Infection Registry) to collect clinical data, bacterial isolates, and serum from patients with S. aureus bone infection. A prospective multinational registry with a 12-month follow-up was created to include adult patients (18 years or older) with culture-confirmed S. aureus infection in long bones after fracture fixation or arthroplasty. Baseline patient attributes and details on infections and treatments were recorded. Blood and serum samples were obtained at baseline, 6, and 12 months. Patient-reported outcomes were collected at 1, 6, and 12 months. Clinical outcomes were recorded. Two hundred and ninety-two patients with fracture-related infection (n = 157, 53.8%), prosthetic joint infection (n = 86, 29.5%), and osteomyelitis (n = 49, 16.8%) were enrolled. Methicillin-resistant S. aureus was detected in 82 patients (28.4%), with the highest proportion found among patients from North American sites (n = 39, 48.8%) and the lowest from Central European sites (n = 18, 12.2%). Patient outcomes improved at 6 and 12 months in comparison to baseline. The SF-36 physical component summary mean (95% confidence interval) score, however, did not reach 50 at 12 months. The cure rate at the end of the study period was 62.1%. Although patients improved with treatment, less than two-thirds were cured in 1 year. At 12-month follow-up, patient-reported outcome scores were worse for patients with methicillin-resistant S. aureus infections.

Shrug radiographs for the diagnosis of long thoracic nerve palsy in traumatic brachial plexus injury

BACKGROUND

Preoperative diagnosis of long thoracic nerve (LTN) palsy is important for shoulder reconstruction after a traumatic brachial plexus injury (BPI). In the present study, we developed an objective diagnostic method for LTN palsy for patients with traumatic BPI.

METHODS

This is a retrospective review of 56 patients with traumatic BPI who had been receiving treatment at a single institution for over 8 years. The patients were divided into 2 groups: an LTN palsy group (n = 30) and a no palsy control group (n = 26). The LTN palsy group had 21 different palsy types with 4 and 5 C5-7 and C5-8, whereas the no palsy group had 18 different palsy types with 5 and 3 C5-6 and C5-8, respectively. Preoperative plain anteroposterior radiographs were taken in shoulder adduction and shrug positions. Scapulothoracic (ST) upward rotation and clavicle lateral (CL) rotation angles were measured on X-rays. The differences between the adduction and shrug positions for the respective angles were calculated and defined as Φ_ST and Φ_CL, respectively. The differences in the Φ_ST and Φ_CL values due to the presence or absence of LTN palsy were examined, the cutoff values of Φ_ST and Φ_CL for the diagnosis of LTN palsy were determined, and further sensitivity and specificity were calculated.

RESULTS

Both Φ_ST and Φ_CL were significantly decreased in the LTN palsy group compared with the no palsy control group. The sensitivity and specificity for LTN palsy were 0.833 and 1.000 for Φ_ST and 0.833 and 0.840 for Φ_CL, respectively, when the cutoff value was set as Φ_ST = 15° and Φ_CL ≤ 24°.

CONCLUSION

Dynamic shrug radiographs provide a useful objective diagnosis of LTN palsy after traumatic BPI.

Ultrasound-guided coracohumeral ligament release

Long-term follow-up of patients with adhesive capsulitis (AC) reveals that approximately half of them suffer from a limited range of shoulder motion, particularly external and/or internal rotation. We report the surgical technique and short-term clinical outcomes of ultrasound-guided release of the thickened coracohumeral (CH) ligament in 8 patients (9 shoulders) with AC. Passive external rotation with the arm by the side significantly increased from an average of 18° preoperatively to 47° immediately after CH ligament release. VAS and ASES scores were improved at 3months follow-up in all 9 shoulders, and maintained at 6months follow-up in 6 shoulders. No procedure-related adverse events developed over the 6-month follow-up period. Ultrasound-guided release for thickened CH ligament is a reliable and effective minimally invasive surgery for persistent limited external rotation due to AC of the shoulder.

Continuous infusion of PTH1-34 delayed fracture healing in mice

Hyperparathyroidism, which is increased parathyroid hormone (PTH) levels in the blood, could cause delayed or non-union of bone fractures. But, no study has yet demonstrated the effects of excess continuous PTH exposure, such as that seen in hyperparathyroidism, for fracture healing. Continuous human PTH_1–34 (teriparatide) infusion using an osmotic pump was performed for stabilized tibial fractures in eight-week-old male mice to determine the relative bone healing process compared with saline treatment. Radiographs and micro-computed tomography showed delayed but increased calcified callus formation in the continuous PTH_1–34 infusion group compared with the controls. Histology and quantitative histomorphometry confirmed that continuous PTH_1–34 treatment significantly increased the bone callus area at a later time point after fracture, since delayed endochondral ossification occurred. Gene expression analyses showed that PTH_1–34 resulted in sustained Col2a1 and reduced Col10a1 expression, consistent with delayed maturation of the cartilage tissue during fracture healing. In contrast, continuous PTH_1–34 infusion stimulated the expression of both Bglap and Acp5 through the healing process, in accordance with bone callus formation and remodeling. Mechanical testing showed that continuously administered PTH_1–34 increased the maximum load on Day 21 compared with control mice. We concluded that continuous PTH_1–34 infusion resulted in a delayed fracture healing process due to delayed callus cell maturation but ultimately increased biomechanical properties.

Isolated Salter-Harris Type III Physeal Fracture of the Distal Ulna

We describe a case of isolated physeal fracture of ulna distal end in a 13-year-old boy. This fracture type is uncommon, especially Salter-Harris type III of this injury has not been reported. Plain radiographs showed a small vertical fracture line at the ulnar distal end and an enlargement of epiphyseal plate at the base of ulnar styloid process. The present case was successfully managed with conservative treatment because of its minimal displacement.

Teriparatide (human PTH1-34) compensates for impaired fracture healing in COX-2 deficient mice

Genetic ablation of cyclooxygenase-2 (COX-2) in mice is known to impair fracture healing. To determine if teriparatide (human PTH_1-34) can promote healing of Cox-2-deficient fractures, we performed detailed in vivo analyses using a murine stabilized tibia fracture model. Periosteal progenitor cell proliferation as well as bony callus formation was markedly reduced in Cox-2^-/- mice at day 10 post-fracture. Remarkably, intermittent PTH_1-34 administration increased proliferation of periosteal progenitor cells, restored callus formation on day 7, and enhanced bone formation on days 10, 14 and 21 in Cox-2-deficient mice. PTH_1-34 also increased biomechanical torsional properties at days 10 or 14 in all genotypes, consistent with enhanced bony callus formation by radiologic examinations. To determine the effects of intermittent PTH_1-34 for callus remodeling, TRAP staining was performed. Intermittent PTH_1-34 treatment increased the number of TRAP positive cells per total callus area on day 21 in Cox-2^-/- fractures. Taken together, the present findings indicate that intermittent PTH_1-34 treatment could compensate for COX-2 deficiency and improve impaired fracture healing in Cox-2-deficient mice.

Ulnar nerve palsy caused by synovial protrusion in synovial chondromatosis of the elbow: a case report and literature review

We describe an unusual case of ulnar nerve compression (cubital tunnel syndrome) caused by synovial protrusion in primary synovial chondromatosis of the elbow in a 59-year-old man. Magnetic resonance imaging is a useful tool for diagnosing this rare condition. Surgical excision of the intra-articular multiple loose bodies and ulnar nerve decompression were performed. The clinician should be aware of primary synovial chondromatosis as one of the causative factors of cubital tunnel syndrome.

Analysis of shoulder abduction by dynamic shoulder radiograph following suprascapular nerve repair in brachial plexus injury

BACKGROUND

Suprascapular nerve repair is a widely-prioritized procedure for shoulder reconstruction following brachial plexus injury. Although this procedure only reconstructs glenohumeral joint motion, the standard clinical assessment of shoulder function also includes the scapulothoracic joint contribution. The purpose of this preliminary study was to develop an objective method to accurately analyze shoulder abduction following suprascapular nerve repair in brachial plexus injury patients.

METHODS

We introduced an objective method to accurately analyze independent shoulder abduction performed by supraspinatus muscle with the help of dynamic shoulder radiography. Antero-posterior radiographs of both shoulders in adduction and maximal active abduction were obtained. Five parameters were measured. They included global abduction, abduction in glenohumeral, scapulothoracic and clavicular joints along with lateral flexion of thoracic spine. Data were analyzed to distinguish glenohumeral joint contribution from that of scapulothoracic motion. The detailed biomechanics of glenohumeral motion were also analyzed in relation to scapulothoracic motion to separately define the contribution of each in global shoulder abduction.

RESULTS

The test-retest, intra-examiner and inter-examiner reliabilities of the measurements were assessed. Intra-class correlation coefficient, Bland-Altman plots and repeatability coefficients showed excellent reliability for each parameter. The range of glenohumeral abduction showed high correlation to subtraction of the range of scapulothoracic from the range of global abduction. However, not all negative ranges of glenohumeral abduction meant non-recovery after nerve repair, because scapulothoracic motion contributed in parallel but not uniformly to global shoulder motion.

CONCLUSION

The conventional measurement of shoulder global abduction with goniometer is not an appropriate method to analyze the results of suprascapular nerve repair in brachial plexus palsy patients. We recommend examination of glenohumeral and scapulothoracic motions separately with dynamic shoulder radiographic analysis. With scapulothoracic contribution to the global shoulder motion, the glenohumeral motion can be wrongly assessed.

Medial tibial plateau morphology and stress fracture location: A magnetic resonance imaging study

AIM

To determine the location of medial tibial plateau stress fractures and its relationship with tibial plateau morphology using magnetic resonance imaging (MRI).

METHODS

A retrospective review of patients with a diagnosis of stress fracture of the medial tibial plateau was performed for a 5-year period. Fourteen patients [three female and 11 male, with an average age of 36.4 years (range, 15-50 years)], who underwent knee MRI, were included. The appearance of the tibial plateau stress fracture and the geometry of the tibial plateau were reviewed and measured on MRI.

RESULTS

Thirteen of 14 stress fractures were linear, and one of them stellated on MRI images. The location of fractures was classified into three types. Three fractures were located anteromedially (AM type), six posteromedially (PM type), and five posteriorly (P type) at the medial tibial plateau. In addition, tibial posterior slope at the medial tibial plateau tended to be larger when the fracture was located more posteriorly on MRI.

CONCLUSION

We found that MRI showed three different localizations of medial tibial plateau stress fractures, which were associated with tibial posterior slope at the medial tibial plateau.

Cystic lesion around the hip joint

This article presents a narrative review of cystic lesions around the hip and primarily consists of 5 sections: Radiological examination, prevalence, pathogenesis, symptoms, and treatment. Cystic lesions around the hip are usually asymptomatic but may be observed incidentally on imaging examinations, such as computed tomography and magnetic resonance imaging. Some cysts may enlarge because of various pathological factors, such as trauma, osteoarthritis, rheumatoid arthritis, or total hip arthroplasty (THA), and may become symptomatic because of compression of surrounding structures, including the femoral, obturator, or sciatic nerves, external iliac or common femoral artery, femoral or external iliac vein, sigmoid colon, cecum, small bowel, ureters, and bladder. Treatment for symptomatic cystic lesions around the hip joint includes rest, nonsteroidal anti-inflammatory drug administration, needle aspiration, and surgical excision. Furthermore, when these cysts are associated with osteoarthritis, rheumatoid arthritis, and THA, primary or revision THA surgery will be necessary concurrent with cyst excision. Knowledge of the characteristic clinical appearance of cystic masses around the hip will be useful for determining specific diagnoses and treatments.

Spontaneous resorption of calcification at the long head of the biceps tendon

Calcific tendinitis of the long head of the biceps tendon is a rare cause of shoulder pain. Calcium deposits are often spontaneously resorbed or reduced in size in the rotator cuff tendons, which represent the most common sites of calcific tendinitis around the shoulder. To our knowledge, no case of spontaneous resorption of calcification in the long head of the biceps tendon has been reported in the literature. Here, we report one such case and describe its successful treatment using a conservative approach.