Substance P, A Promising Therapeutic Target in Musculoskeletal Disorders.

A large number of studies have focused on the role of substance P (SP) and the neurokinin-1 receptor (NK1R) in the pathogenesis of a variety of medical conditions. This review provides an overview of the role of the SP-NK1R pathway in the pathogenesis of musculoskeletal disorders and the evidence for its role as a therapeutic target for these disorders, which are major public health problems in most countries. To summarize, the brief involvement of SP may affect tendon healing in an acute injury setting. SP combined with an adequate conjugate can be a regenerative therapeutic option in osteoarthritis. The NK1R antagonist is a promising agent for tendinopathy, rheumatoid arthritis, and osteoarthritis. Research on the SP-NK1R pathway will be helpful for developing novel drugs for osteoporosis.

The inter-and intra-observer reliability of volar angulation measurements in a fifth metacarpal neck fracture.

INTRODUCTION: The fifth metacarpal neck fracture is the most common metacarpal fracture. The palmar angulation from the fracture displacement is critical for determining treatment, yet there is no consensus regarding the angulation measurement method or the surgical cut-off value. This study aimed to identify a reliable measurement method for assessing palmar angulation. We evaluated inter-observer and intra-observer validation of measuring palmar angulation in oblique plain X-ray and computed tomography (CT) sagittal cuts. MATERIALS AND METHODS: We identified surgically treated patients for acute isolated fifth metacarpal neck fracture between January 1, 2008, and December 31, 2020, and obtained preoperative, opposite hand, and final follow-up oblique X-rays and sagittal computed tomography (CT) radiograms. The oblique radiograph was taken with a 45° posteroanterior pronation. The metacarpal neck palmar angulation was measured in the radiograms using the metacarpal neck-shaft center (MNSC) angle and the shaft articular surface (SAS) angle methods by three orthopedic surgeons in two sessions. For the CT radiograms, each measurer selected the sagittal slot at their discretion to measure the angle. The final palmar angulation was the average of six measurements (two sessions, three measurers per session). RESULTS: The study included 51 patients; the average age was 32.5 (range 18-73) years, with 46 men and 5 women. The MNSC angle inter-observer reliability was better than the SAS angle. The MNSC angle inter-observer reliability was better than that of SAS angle. Intraclass coefficients (ICCs) for the MNSC angle demonstrated an excellent inter-observer agreement among the three measurers in the first (0.93) and second (0.88) session compared to ICCs for the SAS angle in the first (0.81) and second (0.87) session. The MNSC angle intra-observer reliability was also better than the SAS angle, with higher ICCs. Preoperative CT radiograms were available for 42 patients. Using CT scans for measurements, in the two sessions, the MNSC angle inter-observer reliability was higher than that of the SAS angle [MNSC: 0.83; SAS: 0.35], second [MSNC: 0.85; SAS: 0.81]. The intra-observer reliability was also better in the MNSC angle. When comparing average value among obtained radiograms, the physiologic angulation of the opposite hand oblique X-ray had the smallest average value, followed by preoperative CT and preoperative oblique radiography. Overall, the SAS angle measurement had a slightly larger angle than the MNSC method in the fractured and non-fractured hand measurements. Finally, a serial comparison of the oblique X-rays (pre-and postoperative, final follow-up, and the opposite hand with closed reduction and internal fixation) indicated that the angulation significantly decreased, and the post-operative values did not differ from the final follow-up X-ray for either method. CONCLUSIONS: The palmar angulation measurement in 45° pronated oblique X-ray using the MNSC angle method had good-to-excellent reliability, with superior results to sagittal CT radiograms. Although the angle is likely overestimated, the MNSC method is reliable for judging the fracture degree and reduction adequacy after surgery compared to the non-fractured hand physiologic angulation.

Long-term outcomes of the modified Nirschl technique for lateral Epicondylitis: a retrospective study.

BACKGROUND: Although the Nirschl technique was introduced approximately 40 years ago, only limited information is available about the long-term results, especially concerning extensor power changes after surgery. The purpose of this study was to investigate long-term clinical results of surgical treatment of lateral epicondylitis using the modified Nirschl technique. The main outcome variable was muscle strength for wrist extension because the extensor origin was not reattached after removal of the degenerative extensor tendon. METHODS: Data from 99 patients who underwent surgical lateral epicondylitis treatment between 2007 to 2012 were included in the study. The mean follow-up period was 8.5 years (5 to 10, ± 1.1 years) and the mean age at surgery was 44.8 years (32 to 70, ± 9.8 years). The surgeries were performed using the modified Nirschl method and did not include extensor origin reattachment. Outcome measurements included the Visual Analogue Scale (VAS) score, Disabilities of the Arm, Shoulder and Hand (DASH) score, the MAYO elbow performance score, and Nirschl and Pettrone's grades. Wrist extension and grip strength were analyzed using a digital handgrip dynamometer (microFET2TM system) and JAMA hand dynamometer. RESULTS: Mean time required to return to work was 2.4 months after surgery. At the last follow-up after surgery, the mean VAS score had significantly improved, from 4.9 to 1.1. Mean MAYO elbow performance scores significantly improved, from 64 to 90, and mean DASH scores improved from 50 to 13. The Nirschl and Pettrone's grades were 80% rated as 'excellent' and 16% rated as 'good'. After adjusting for power differences between the dominant and non-dominant arms, the difference between wrist extensor power of the operated elbow and the non-operated opposite elbow at the final follow-up was not statistically significant. No patients complained about wrist extension weakness. CONCLUSION: Although reattachment of the extensor origin was not performed during the modified Nirschl surgical technique, there was no significant weakness in wrist extension power and the long-term follow-up revealed favorable clinical results. LEVEL OF EVIDENCE: Level IV (case series). Retrospective study.

The expression of substance P and calcitonin gene-related peptide is associated with the severity of tendon degeneration in lateral epicondylitis.

BACKGROUND: In this study, we investigated whether substance P (SP) or calcitonin gene-related peptide (CGRP) expression is associated with tendon degeneration in patients with lateral epicondylitis. METHODS: Twenty-nine patients who underwent surgical treatment for lateral epicondylitis were enrolled in the final analyses. Extensor carpi radialis brevis tendon origins were harvested for histological analysis. RESULTS: SP and CGRP immunostaining were negative in healthy tendons but positive in degenerative tendons; moreover, their immunoreactivity increased with degeneration severity. Univariate analysis indicated that variables such as the preoperative visual analog scale (VAS) score or SP or CGRP expression levels were significantly associated with the Movin score. However, multivariate analysis revealed that only higher SP and/or CGRP signals were associated with higher Movin scores. Elevations in SP or CGRP expression were also linked with significantly severe preoperative VAS scores. CONCLUSION: We demonstrated that tendon degeneration severity is associated with increased SP and CGRP expression in the biopsy samples of lateral epicondylitis.

Carpal Tunnel Release Despite Normal Nerve Conduction Studies in Carpal Tunnel Syndrome Patients.

PURPOSE: Carpal tunnel syndrome (CTS) is a common entrapment neuropathy, often requiring carpal tunnel release (CTR) surgery. Often, a nerve conduction study (NCS) is performed before CTR; however, there are various reports questioning the sensitivity of NCS, and some patients do undergo CTR despite normal NCS results. We had the following purposes: (1) to report clinical outcome of CTS patients who undergo CTR despite normal NCS, (2) to identify the characteristics and compare those with abnormal NCS patients in terms of basic features and risk factors, and (3) to analyze and compare normal and abnormal NCS results. MATERIALS AND METHODS: Medical records of 546 CTS (30 normal NCS and 516 abnormal NCS) patients were retrospectively reviewed. Of 30 normal NCS patients, 7 were excluded, leaving 23 patients in the experimental group. We investigated the influence of age, sex, operative arm, and body mass index, as well as medical conditions known to be risk factors for CTS. In normal NCS patients, as a functional score, we investigated Boston carpal tunnel scores before and after CTR. The NCS results were compared in terms of median motor and median sensory testing. In normal NCS patients, NCS data were compared with that of the contralateral nonoperated wrists. RESULTS: There were 18 women and 5 men in the normal NCS group (mean age 43.7 years). On physical examination, 22 (94.7%) patients showed a positive Tinel test, 19 (82.6%) showed a positive Phalen test, 8 (34.8%) complained of nocturnal paresthesia, and only 1 (4.3%) presented with thenar atrophy. In 19 of 23 patients, the Boston CTS scores showed significant improvement after CTR. Normal NCS patients were significantly younger and significantly heavier and more likely to be a current smoker. In NCS analysis of normal NCS patients, the operated wrists were closer to the reference values than nonoperated wrists. CONCLUSIONS: Surgeons should evaluate the possibility of other combined lesions before CTR in normal NCS patients. Normal NCS can be present with a CTS diagnosis, especially in younger patients. Nevertheless, CTR after failed conservative management, despite normal NCS, could relieve subjective symptoms and function.

Volar locking plate removal after distal radius fracture: a 10-year retrospective study.

INTRODUCTION: Distal radius fracture (DRF) is the most common upper extremity fracture. After the introduction of volar locking plate (VLP) fixation, treatment has shifted from conservative management to more operative management. The implant removal rate after VLP fixation in patients with DRF varies and the reasons for removal and associated patient characteristics have not been clearly defined. This study aimed to compare the characteristics of patients who underwent VLP with and without subsequent implant removal. Second, the rate of implant removal according to the implant position and type was investigated. Finally, we summarized clinical outcome with implant removal, the reasons for, and complications associated with implant removal. METHODS: In this retrospective study, patient data were collected between January 1, 2008, and December 31, 2017. The study population was divided into two groups based on subsequent implant removal. Data on patient characteristics, such as age, sex, comorbidities, side of the fractured arm, the AO Foundation and Orthopaedic Trauma Association classification of the DRF, plate position grade based on the Soong classification type, type of inserted plate, insurance coverage, and treatment costs were collected. Furthermore, we investigated the reason for implant removal, clinical outcomes, and post-removal complications. RESULTS: After applying the exclusion criteria, 806 patients with a total of 814 DRFs were included in the study. Among the 806 patients who underwent VLP fixation for DRF, 252 (31.3%) patients underwent implant removal. Among the patients undergoing implant removal, the mean age was 50.8 ± 14.0 years, 94 (37.3%) were male. The average time to implant removal from the fracture fixation was 12.1 ± 9.2 months (range 1-170 months). When comparing groups, patients who underwent implant removal were significantly younger and had fewer cases of diabetes, hypertension, and cancer history. According to the Soong plate position grade, the most common position was G1 in both groups. Although there was no significant difference (p = 0.075), more G2 cases were found in the removal group (15.0%) than in the retention group (10.2%). About 66.5% of the patients with implant removal had other health insurance as well as the national service, compared with 47% of the patients with implant retention. In total, 186 patients (73.8%) underwent implant removal despite being asymptomatic after the bony union. The patient satisfaction scores improved from 4.1 to 4.4 after implant removal, and 93% of the patients answered that they would choose implant removal again. Only 10% of the patients who underwent removal reported minor complications. No major complications were reported. CONCLUSION: Although the implant removal was conducted without clinical symptoms in the majority of patients, overall patients presented improved functional outcomes with implant removal. The evidence is inconclusive regarding its necessity, however, implant removal after VLP fixation for DRF is not a challenging procedure and is not associated with major complications. LEVEL OF EVIDENCE: Level IV.

Complications associated with volar locking plate fixation for distal radius fractures in 1955 cases: A multicentre retrospective study.

PURPOSE: Since volar locking plates (VLPs) have the benefits of more stable fixation and fewer complications, VLP osteosynthesis is now the preferred osteosynthesis method in the operative management of distal radius fractures (DRF). Along with the increases in operative management of VLP, the character and frequency of complications have changed. Thus, this multicentre study aimed to identify the characteristics of patients with DRFs who were treated with VLP fixation, describe the complication types and rates related to the procedure, and compare the results with those found in the literature. MATERIAL AND METHODS: This retrospective multicentre study was conducted between January 2008 and December 2017. In total, data from 2225 patients over 17 years old who underwent VLP fixation for DRF were screened. Patients with closed reduction and pinning, external fixation, dorsal plate fixation, and screw-only fixation were excluded. Finally, 1955 wrists from 1921 patients (86.3%) were included. The following types of complications were investigated: (1) tendon injury, (2) nerve-related, (3) fixation- and instrument-related, (4) osteosynthesis-related, (5) infection, and (6) others. RESULTS: The mean age of the patients was 60.3 ± 14.6 years with 587 males (30.6%). Distal ulnar fractures were found in 940 wrists (48.1%). The mean interval between fracture and surgery was 6.2 days, while the mean operative time was 68.3 ± 30.3 minutes. The following complications were found: (1) nine (0.46%) and 12 (0.61%) cases of flexor pollicis longus and complete extensor pollicis longus tears, respectively; (2) nine cases (0.46%) of palmar sensory median nerve branch damage, 15 cases (0.77%) of complex regional pain syndrome, and 36 cases (1.84%) of carpal tunnel syndrome; (3) five cases (0.26%) of fracture displacement even after plate fixation, six cases (0.31%) of screw breakage, 26 cases (1.33%) of radiocarpal joint screw penetration, and 511 cases (26.14%) of implant removal; (4) five cases (0.26%) of delayed union and three cases (0.15%) of non-union; (5) 83 (4.25%) and two (0.1%) cases of superficial and deep infection, respectively; and (6) two cases (0.1%) of compartment syndrome and three cases (0.15%) of radial artery damage. CONCLUSIONS: After 10 years of experience performing VLP fixation for DRFs in a multicentre setting, the results regarding complication types and rates support its use as a reasonable treatment option with low rates of complication.

Sustained Exposure of Substance P Causes Tendinopathy.

Recently, neuromediators such as substance P (SP) have been found to be important factors in tendon homeostasis. Some studies have found SP to be the cause of inflammation and tendinopathy, whereas others have determined it to be a critical component of tendon healing. As demonstrated by these conflicting findings, the effects of SP on tendinopathy remain unclear. In this study, we hypothesized that the duration of SP exposure determines its effect on the tendons, with repetitive long-term exposure leading to the development of tendinopathy. First, we verified the changes in gene and protein expression using in vitro tenocytes with 10-day exposure to SP. SP and SP + Run groups were injected with SP in their Achilles tendon every other day for 14 days. Achilles tendons were then harvested for biomechanical testing and histological processing. Notably, tendinopathic changes with decreased tensile strength, as observed in the Positive Control, were observed in the Achilles in the SP group compared to the Negative Control. Subsequent histological analysis, including Alcian blue staining, also revealed alterations in the Achilles tendon, which were generally consistent with the findings of tendinopathy in SP and SP + Run groups. Immunohistochemical analysis revealed increased expression of SP in the SP group, similar to the Positive Control. In general, the SP + Run group showed worse tendinopathic changes. These results suggest that sustained exposure to SP may be involved in the development of tendinopathy. Future research on inhibiting SP is warranted to target SP in the treatment of tendinopathy and may be beneficial to patients with tendinopathy.

Kienböck's disease with non-negative ulnar variance : Treatment with combined radial wedge and shortening osteotomy.

PURPOSE: There are only few studies that focused on Kienböck's disease with non-negative ulnar variance, even though many surgical procedures have been introduced. A combined radial wedge and shortening osteotomy was carried out for Kienböck's disease with non-negative ulnar variance. The purpose of this article is to report the results of this procedure by analyzing the clinical and radiological data. MATERIAL AND METHODS: The data for patients with Kienböck's disease who were treated by combined radial wedge and shortening osteotomy between 2007 and 2016 were retrospectively reviewed. A total of 18 patients (8 males, 10 females), average age 37 years, were included in this study and the mean follow-up period was 22.3 months. Radiological analysis included Lichtman stage, ulnar variance, radial inclination, carpal height ratio, radioscaphoid angle and Stahl's index. Clinical analysis included range of motion (ROM), visual analog scale (VAS) score, grip power, modified Mayo wrist score (MMWS), and disabilities of arm, shoulder and hand (DASH) score. RESULTS: Preoperative radiological analysis showed 16 cases of Lichtman stage IIIA and 2 cases of stage IIIB. Preoperative ulnar variance was +0.51 mm, radial inclination was 27.7o, carpal height ratio was 0.49, radioscaphoid angle was 52.8o and Stahl's index was 0.42. All patients had solid union at the osteotomy site. At the final follow-up the average ulnar variance was +1.9 mm, radial inclination was 16.5o, carpal height ratio was 0.48, radioscaphoid angle was 58.2o and Stahl's index was 0.36. Clinical analysis showed that the average dorsiflexion of the wrist was increased by 8.4o and palmar flexion of the wrist was increased by 29.6o. Grip power was increased by an average of 9.9 kg. Average VAS at the final follow-up was 1.0, DASH score was 4.3, and modified Mayo wrist score was 78.1. CONCLUSION: Radial wedge and shortening osteotomy can be recommended as an option for Kienböck's disease with non-negative ulnar variance, based on acceptable results from this study.

Dual plate fixation on distal third diaphyseal fracture of the humerus.

INTRODUCTION: Displaced unstable distal third fractures of the humeral diaphysis are treated surgically through open reduction and internal fixation. Conventionally, surgeons prefer using long plates for secure fixation; however, we performed short plate dual plating for robust fixation that required a smaller incision and less dissection through an anterior approach. In this study, we report the results of dual plating of fractures of the humeral shaft, with radiographic evidence and clinical analysis. METHODS: This retrospective study included 29 patients with distal third diaphyseal fractures of the humerus. There were 18 men and 11 women, with an average age of 43 years, and a mean follow-up period of 21.2 months. We investigated the type of fracture, plate length, number of fixed screws, and fracture union. Range of motion, Disabilities of Arm, Shoulder, and Hand (DASH) score, and complications during follow-up were analyzed for clinical results. RESULTS: All fractures were classified according to AO classification. We used 4.5-mm narrow locking compression plates (LCP) and 3.5-mm LCP reconstruction plates. Fracture union was achieved in all cases during the follow-up. All patients recovered favourable elbow range of motion at final follow-up. At the final follow-up, average DASH score was 10.0, and no patient showed postoperative complications. CONCLUSIONS: Satisfactory radiographic evidence and clinical results suggest that dual plating for distal diaphyseal humeral fractures may be considered a surgical option, with the advantages of strong fixation, less invasion of soft tissue, and early rehabilitation.

The Implication of Substance P in the Development of Tendinopathy: A Case Control Study.

It was reported that substance P had beneficial effects in the healing of acute tendon injury. However, the relationship between substance P and degenerative tendinopathy development remains unclear. The purpose of this study was to determine the role of substance P in the pathogenesis of tendinopathy. Healthy and tendinopathy tendon were harvested from human and tenocytes were cultured individually. The expression levels of genes associated with tendinopathy were compared. Next, substance P was exogenously administered to the healthy tenocyte and the effect was evaluated. The results showed that tendinopathy tenocytes had higher levels of COL3A1, MMP1, COX2, SCX, ACTA2, and substance P gene expression compared to healthy tenocytes. Next, substance P treatment on the healthy tenocyte displayed similar changes to that of the tendinopathy tenocytes. These differences between the two groups were also determined by Western blot. Additionally, cells with substance P had the tendinopathy change morphologically although cellular proliferation was significantly higher compared to that of the control group. In conclusion, substance P enhanced cellular proliferation, but concomitantly increased immature collagen (type 3 collagen). Substance P plays a crucial role in tendinopathy development and could be a future therapeutic target for treatment.

Direct repair of the sagittal band for extensor tendon subluxation caused by finger flicking.

PURPOSE: For patients with metacarpophalangeal (MCP) extensor tendon subluxation caused by finger flicking injury, we performed an extensor tendon realignment and direct repair technique. The purpose of this study was to evaluate the clinical outcome after direct repair of the sagittal band in patients with MCP extensor tendon subluxation caused by finger flicking injury and to introduce the repair technique. METHODS: A total of 26 patients with a mean age of 39.9 years were included in the study. The mean time from injury to surgery was 51.3 days. The ruptured sagittal band was reattached to the lateral side of the extensor tendon using a continuous interlocking suture. Patients were evaluated for pain using a visual analog scale (VAS), range of motion, long fingertip pinch strength, disabilities of the arm, shoulder, and hand (DASH) score, and the recurrence of extensor tendon subluxation or dislocation. RESULTS: All patients had full range of motion compared to the uninjured contralateral digit. Long fingertip pinch strength was also comparable to that of the contralateral digit in all patients. The DASH score was also improved from a preoperative average of 28.8 to a postoperative average of 1.0. CONCLUSIONS: Realignment of the extensor tendon and direct repair of the superficial layer of the sagittal band to the extensor digitorum communis (EDC) tendon is recommended as a treatment option in patients with chronic MCP extensor tendon subluxation, as well as for acute MCP extensor tendon subluxation in patients that have failed or could not maintain conservative treatment approaches.

Open reduction and internal fixation for intraarticular fracture of metacarpal head.

Intraarticular fracture of the metacarpophalangeal (MP) joint presents complex problems related to the sophisticated functional aspects of the hand. Injury to the metacarpal head may have a severe effect on hand function but few studies have investigated the management of this condition. In this study, we applied open reduction and internal fixation for the displaced fracture of the metacarpal head and report the clinical and radiographic outcomes of our experience. Thirteen patients (12 men, 1 woman; mean age 21 years) were included in this study, and medical records and radiographs were reviewed retrospectively. The average follow-up period was 12.5 months. Range of motion (ROM) and Disabilities of the Arm, Shoulder, and Hand (DASH) scores were analyzed, and functional results and serial radiographs were investigated for the maintenance of articular congruity and fracture union. The injured fingers were 5 long, 4 small, 2 ring, and 2 index. Five cases were fixed with K­wires, 5 cases with headless screws, and 3 cases with screw and K­wire. The average range of injured MP joint motion was 89°, total active range of motion (TAM) was 265°, and the average DASH score was 3.8 at the last follow-up. All patients showed fracture union on the radiographs and no patient showed significant articular surface incongruence or degenerative change. Open reduction and internal fixation of the metacarpal head fracture had favorable outcomes in our study. The authors suggest accurate reduction and stable fixation for better functional results in metacarpal head fractures.

The result of surgical treatment of medial epicondylitis: analysis with more than a 5-year follow-up.

BACKGROUND: Angiofibroblastic changes of a musculotendinous origin at the medial epicondyle characterize medial epicondylitis of the elbow. Although nonsurgical treatment is the primary approach for medial epicondylitis, surgical treatment should be considered when conservative therapy fails. This study reports the results of surgical treatment of medial epicondylitis monitored for more than 5 years. METHODS: This study included 55 patients with 63 cases of medial epicondylitis between 2000 and 2010. The conservative treatment periods lasted for a minimum of 1 year, and steroid injections were administered more than twice before surgery. One surgeon conducted the surgical procedures. The Nirschl and Pettrone grades, visual analog scale (VAS) scores, Disabilities of the Arm, Shoulder and Hand (DASH) scores, Mayo Elbow Performance scores, and grip strengths were analyzed. Statistical analyses were performed using paired t tests. RESULTS: The mean VAS score improved from 8.5 to 2.4 (P <.001). Nirschl and Pettrone grades rated 43% (27 elbows) as excellent and 51% (32 elbows) as good. The Mayo Elbow Performance scores improved from 72 to 88 (P <.001) and DASH scores from 57 to 23 (P <.001). The mean grip strength of the affected side improved from 30 to 43 lb (P <.001). The mean time required to return to work and exercise was 2.8 months and 4.8 months, respectively. One case of heterotrophic ossification, which had no functional instability afterward, was seen. CONCLUSION: The results indicate that surgical treatment of medial epicondylitis could be an effective and safe treatment when conservative treatment fails.

Association of Plasminogen Activator Inhibitor-1 (PAI-1) Gene Polymorphisms with Osteoporotic Vertebral Compression Fractures (OVCFs) in Postmenopausal Women.

Osteoporosis and osteoporotic fractures are strongly associated with mortality and morbidity, both in developing and developed countries. Menopause accelerates bone loss due to estrogen deficiency and age-related linear bone loss. We investigated plasminogen activator inhibitor-1 (PAI-1) gene polymorphisms in postmenopausal women with osteoporotic vertebral compression fractures (OVCFs). In this case-control study, 355 postmenopausal women were genotyped for the presence of PAI-1 gene polymorphisms -844A > G, -675 4G > 5G, 43G > A, 9785A > G, and 11053T > G. Genetic polymorphisms of PAI-1 were analyzed by the polymerization chain reaction restriction fragment length polymorphism assay, and their association with disease status and folate and homocysteine levels was determined in 158 OVCF patients and 197 control subjects. The PAI-1 -675 5G5G (adjusted odds ratio (AOR), 3.302; p = 0.017) and 43GA + AA (AOR, 2.087; p = 0.042) genotype frequencies showed significant association with the increased prevalence of OVCFs in postmenopausal women. In addition, we performed gene-environment interaction studies and demonstrated an association between PAI-1 gene polymorphisms and OVCF prevalence. Our novel finding is the identification of several PAI-1 genetic variants that increase susceptibility to OVCF. Our findings suggest that polymorphisms in PAI-1 may contribute to OVCF, and that they can be developed as biomarkers for evaluating OVCF risk.

Complications of the Intramedullary Skeletal Kinetic Distractor (ISKD) in distraction osteogenesis.

BACKGROUND: The Intramedullary Skeletal Kinetic Distractor (ISKD) (Orthofix Inc, Lewisville, TX, USA) is an intramedullary device designed for more comfortable limb lengthening than that with external fixators; lengthening is achieved with this nail using rotational oscillation between two telescoping sections. However, the degree to which this device achieves this goal and its complication rate have not been fully documented. QUESTIONS/PURPOSES: We determined (1) the frequency with which distraction was not achieved at the desired rate, (2) whether pain differed between patients with normally and abnormally distracting nails, (3) risk factors for abnormal nails, and (4) other complications. METHODS: We analyzed 35 lengthening segments (26 femurs, nine tibias) in 19 patients. Mean length achieved was 47 mm. Femoral nails were categorized into four groups according to distraction rate: normal, runaway (unintentionally faster rate [> 1.5 mm/day]), difficult-to-distract (slower rate [< 0.8 mm/day] requiring manual manipulation but not requiring general anesthesia), and nondistracting (slower rate [< 0.8 mm/day] requiring manual manipulation under general anesthesia or reosteotomy). Possible risk factors, including age, BMI, preoperative thigh circumferences, degree of intramedullary overreaming, and length of the thicker portion of the nail within the distal fragment, were compared among groups. VAS pain scores were compared among groups under three conditions: rest, physiotherapy, and distraction motion. Complications were also analyzed. Minimum followup was 15 months (mean, 26 months; range, 15-38 months) after first-stage surgery. RESULTS: Abnormal distraction rate was observed in 21 of 35 segments (60%; 17 femurs, four tibias). VAS pain scores showed no differences among groups during rest or physiotherapy but were higher (p = 0.02) in the problematic nails (7-8 points) versus normal nails (3 points) during distraction. Only mean length of the thicker portion of the nail within the distal fragment differed between normally and abnormally distracting nails (95 mm versus 100 mm; p = 0.03), although this was unlikely to be clinically important. Complications occurred in 10 patients (53%), including five with decreased ankle ROM during distraction, four with delayed bone healing, and one with mechanical device failure during distraction. CONCLUSIONS: Rate control was difficult to achieve with the ISKD nail for femoral and tibial lengthenings, complications were relatively common, and among patients in whom rate control was not achieved, pain levels were high. Based on our findings, we believe that surgeons should avoid use of this nail. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

LCP distal ulna plate fixation of irreducible or unstable distal ulna fractures associated with distal radius fracture.

PURPOSE: The advent of locking compression plate (LCP) has provided convenient and secure fixation of distal ulna fractures. This study was performed to evaluate the functional and clinical outcomes following LCP distal ulna plate fixation of irreducible or unstable distal ulna fractures with concomitant distal radius fractures. METHODS: Retrospective review of 17 patients who had been treated with LCP distal ulna plates for distal ulna fractures was performed. The average age of the patients was 58.9 years (range 21-87 years), and the mean follow-up period was 15 months (range 12-20 months). This study consisted of eleven fractures involving metaphysis and six ulna styloid base fractures. Fracture union, radiologic parameters, stability of the distal radioulnar joint (DRUJ), and functional outcomes, including ROM, grip strength, and functional scores were evaluated. RESULTS: All patients showed bony union, the average radial height was 10.5 mm, and the ulnar variance was 0.8 mm on final radiographs. None of the patients had instability of the DRUJ compared with the opposite wrist, and the subluxation ratio was within normal range on the follow-up CT scan. There were 6 excellent and 11 good cases according to Sarmiento's modified wrist score at the last follow-up. CONCLUSIONS: Locking compression plate distal ulna plate fixation of irreducible or unstable distal ulna fractures after stabilization of concomitant distal radius fractures showed favorable results in union, alignment, and functional outcomes and therefore could be one of the recommendable implant options for distal ulna fractures.

Clinical outcomes of extensor indicis proprius tendon transfer for extensor pollicis longus tendon rupture.

LEVEL OF EVIDENCE: IV.

Anterolateral Dual Plate Fixation for Distal Metaphyseal-Diaphyseal Junction Fractures of the Humerus: Biomechanical Finite Element Analysis with Clinical Results.

Background: Distal metaphyseal-diaphyseal junction fractures of the humerus are a subset of injuries between humeral shaft fractures and distal intra-articular humerus fractures. A lack of space for distal fixation and the unique anatomy of concave curvature create difficulties during operative treatment. The closely lying radial nerve is another major concern. The aim of this study was to determine whether anterolateral dual plate fixation could be effective for a distal junctional fracture of the humerus both biomechanically and clinically. Methods: A right humerus 3-dimensional (3D) model was obtained based on plain radiographs and computed tomography data of patients. Two fractures, a spiral type and a spiral wedge type, were constructed. Three-dimensional models of locking compression plates and screws were constructed using materials provided by the manufacturer. The experiment was conducted by using COMSOL Multiphysics, a finite element analysis, solver, and simulation software package. For the clinical study, from July 2008 to March 2021, a total of 72 patients were included. Their medical records were retrospectively reviewed to obtain patient demographics, elbow range of motion, Disabilities of the Arm, Shoulder and Hand (DASH) scores, Mayo Elbow Performance Scores (MEPS), and hand grip strength. Results: No fracture fixation construct completely restored stiffness comparable to the intact model in torsion or compression. Combinations of the 7-hole and 5-hole plates and the 8-hole and 6-hole plates showed superior structural stiffness and stress than those with single lateral plates. At least 3 screws (6 cortices) should be inserted into the lateral plate to reduce the load effectively. For the anterior plate, it was sufficient to purchase only the near cortex. Regarding clinical results of the surgery, the range of motion showed satisfactory results in elbow flexion, elbow extension, and forearm rotation. The average DASH score was 4.3 and the average MEPS was 88.2. Conclusions: Anterolateral dual plate fixation was biomechanically superior to the single-plate method in the finite element analysis of a distal junctional fracture of the humerus model. Anterolateral dual plate fixation was also clinically effective in a large cohort of patients with distal junctional fractures of the humerus.

Anterior approach for fixation of isolated type III coronoid process fracture.

Authors chose anterior approach through the antecubital fossa for better exposure in that case of isolated coronoid process fracture. The objective of the study was to report validity of anterior approach for the Regan and Morrey type III, isolated fracture of the coronoid process of the ulna without residual valgus or varus instability. From January 2007 and January 2010, we evaluated eleven consecutive patients (7 men, 4 women; mean age 44 years; range 25-67 years) who underwent surgical fixation through the anterior approach. The mean follow-up period was 21 months (range 15-34 months). Preoperative and follow-up roentgenograms were evaluated for assessment of the fracture configuration and confirmation of fracture union. Clinical evaluation included an analysis of surgical complication, range of motion, Mayo elbow performance score, and DASH (disability of the arm, shoulder, and hand) score. Fractures were mainly fixed with plate and screws in 8 cases, cannulated screws in 3 cases. There was no residual joint instability after fracture fragment fixation. All fractures were united, and the average union time was 15.2 weeks with a range of 11-20 weeks. Mean flexion contracture of the elbow was 3.6° (range 0°-10°), and further flexion was 130.9° (range 125°-140°) at the last follow-up. Mean Mayo elbow performance score was 92.3 (range 80-100 points), and mean DASH score was 5.9 (range 1.6-8.3 points). In conclusion, Primary fixation of the coronoid process fractures through the anterior approach could be particularly useful in the Regan and Morrey type III isolated coronoid process fractures.