Acute blockage of forearm supination due to flap tear of the triangular fibrocartilage disc: A case report.

RATIONALE: Acute blockage of forearm supination has been reported in several studies. It is caused by loose bodies in the wrist joint, extensor carpi ulnaris tendon interposition, and distal radioulnar joint (DRUJ) injuries, including forearm bone fractures. Some studies have reported cases of DRUJ injuries caused by triangular fibrocartilage complex (TFCC) tears.We report a case of acute blockage of forearm supination after minor trauma and suggest a possible TFCC tear when a patient complains of forearm supination blocking. In addition, we present a comparison between our case and other reports on etiology, magnetic resonance imaging (MRI) findings, and arthroscopic findings, and show the specific characteristics of our case. PATIENTS CONCERNS: A 22-year-old male presented with left wrist pain as the chief complaint. He was injured 2 months prior to pushing his left hand on the floor during exercise. Physical examination showed a relative limitation of range of motion (ROM) in the left wrist of about 10° in flexion and about 15° in extension compared with the right side. The patient also complained of supination limitation and volar side wrist pain during supination. The patient showed tenderness in the axial compression test. DIAGNOSES: Plain radiographs showing no abnormalities. MRI showed a TFCC tear in the central portion. A torn flap of the TFCC was interposed on the volar side of the DRUJ. INTERVENTIONS: Arthroscopic surgery of the left wrist joint was performed. Arthroscopic examination revealed a tear in the TFCC on the radial side. A torn flap was interposed on the volar side of the DRUJ. We removed the flap from the DRUJ using an arthroscopic grasper and partially resected it. OUTCOMES: Intraoperative tests showed no locking and the forearm was well supinated. Two months after the surgery, the patient had no pain and showed full forearm supination. LESSONS: DRUJ blocking due to a TFCC tear should be suspected when acute blockage of forearm supination occurs after minor trauma. MRI is helpful for diagnosis; however, we suggest that the diagnosis should be confirmed through arthroscopy. Symptoms can be resolved by surgical treatment using arthroscopy.

Analyzing the reduction quality of the distal radioulnar joint after closed K-wire transfixation in a cadaver model: is supination or neutral position superior?

INTRODUCTION: Distal radioulnar joint (DRUJ) instabilities are challenging and their optimal treatment is controversial. In special cases or when reconstruction of the stabilizing triangular fibrocartilage complex (TFCC) fails, K-wire transfixation can be performed. However, no consensus has been reached regarding the rotational position of the forearm in which this should be done. Therefore, it was investigated whether anatomical reduction would best be achieved by transfixation in neutral position or supination of the forearm. MATERIALS AND METHODS: Twelve cadaveric upper limbs were examined before dissection of the DRUJ stabilizing ligaments and after closed transfixation in both positions by C-arm cone-beam CT. Whether this was first done in neutral position or in supination was randomized. The change in the radioulnar ratio (RR) in percentage points (%points) was analyzed using Student's t-test. RR was used since it is a common and sensitive method to evaluate DRUJ reduction, expressing the ulnar head's position in the sigmoid notch as a length ratio. RESULTS: The analysis showed an increased change in RR in neutral position with 5.4 ± 9.7%points compared to fixation in supination with 0.2 ± 16.1%points, yet this was not statistically significant (p = 0.404). CONCLUSIONS: Neither position leads to a superior reduction in general. However, the result was slightly closer to the anatomical position in supination. Thus, transfixation of the DRUJ should be performed in the position in which reduction could best be achieved and based on these data, that tends to be in supination. Further studies are necessary to validate these findings and to identify influential factors.

Effects of simulated radioulnar synostosis on supination and pronation in cats. A cadaveric study.

OBJECTIVE: To evaluate the effect of an induced synostosis with a screw on pronation and supination in cats. STUDY DESIGN: Ex vivo biomechanical study. SAMPLE POPULATION: A total of 58 feline forelimbs. METHODS: A total of 58 cadaveric feline thoracic limbs were mounted on a custom-built jig with the elbow and carpus flexed at a 90° angle. To exclude any orthopedic disease, radiographs of the forelimbs were performed prior to the mechanical tests. Radioulnar synostosis was imitated with a 2 mm cortical screw through the radius into the ulna in the proximal (Group P; n = 54), middle (Group M; n = 52), and distal (Group D; n = 53) radial diaphysis. The angles of pronation and supination were recorded after manually applying a two-finger tight rotational force to the metacarpus. Rotational tests were performed without a screw (Group N) and with a screw in each of the aforementioned positions. Pairwise comparisons between the groups were performed based on their angles of rotation with a paired t-test with the Benjamini-Hochberg procedure and a mixed model ANOVA. RESULTS: Mean angles of rotation decreased between Group N (129.5 ± 15.9°) and all groups with imitated radioulnar synostosis to a mean angle of 37.5 ± 14.5° (p < .0001). Mean angles of rotation did not differ between the groups with imitated radioulnar synostosis. CONCLUSION: Induced radioulnar synostosis decreases antebrachial rotation by more than two-thirds, regardless of location. CLINICAL SIGNIFICANCE: Implants fixating the radius to the ulna should be avoided in cats, regardless where they are located along the radial diaphysis.

Comparative Analysis of Intramedullary Nail versus Plate Fixation for Fibula Fracture in Supination External Rotation Type IV Ankle Injury.

BACKGROUND Lateral malleolus fractures, typically from trauma, sports, or accidents, are common, with supination external rotation (SER) injuries being most prevalent. SER injuries involve complex joint mechanics and often necessitate surgical intervention for instability. This study compares intramedullary nail and plate fixation for fibula fractures in SER type IV ankle injuries, considering their biomechanical properties and influence on fracture healing. MATERIAL AND METHODS A prospective, randomized study was conducted between January 2021 and December 2021. A total of 81 patients with SER injuries were included in the study. Surgical procedures were performed using either intramedullary nails or plates. The following parameters were recorded and analyzed: postoperative complications, operation times, bone healing times, American Orthopaedic Foot & Ankle Society (AOFAS) scores, visual analog scale (VAS) scores for pain, and ankle range of motion. RESULTS Out of the 81 cases, 42 were treated with intramedullary nails, while 39 received plate fixation. Statistical analysis revealed a significantly lower rate of postoperative complications in the intramedullary nail group than in the the plate fixation group (9.52% vs 30.77%, P<0.0164). However, there were no significant differences between the 2 groups in terms of operation time, bone healing time, AOFAS scores, VAS scores, and functional evaluations (P>0.05). CONCLUSIONS Plate fixation and intramedullary nail fixation are effective techniques for treating fibula fractures in SER type IV injuries. However, intramedullary nail fixation demonstrates a lower rate of complications. Therefore, intramedullary nails may be preferable to plate fixation for the management of fibula fractures in SER type IV ankle injuries.

Proximal Supination Osteotomy for Hallux Valgus: Comparison of Clinical and Radiologic Outcomes for the Most Severe Deformities.

BACKGROUND: There is little available information regarding the difference in outcomes between severe hallux valgus (S-HV), defined as 40 degrees ≤ hallux valgus angle (HVA) < 50 degrees, and what we consider to be "super-severe HV" (SS-HV), defined as >50 degrees, following a proximal metatarsal osteotomy. We aimed to retrospectively compare the outcomes of a proximal metatarsal osteotomy in S- and SS-HV. METHODS: The series consisted of 57 female patients (57 feet) treated with a proximal supination osteotomy for symptomatic S- and SS-HV (33 and 24 feet, respectively). The outcome measures included radiographic parameters and for 45 patients included the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) score, and a visual analog scale pain score (VAS-PS) preoperatively and at a minimum follow-up of 12 months with a median of 26 months. No significant differences were found in age, body mass index, and the duration of follow-up between patients with S-HV and SS-HV (P > .10 for all comparisons) with the numbers available. RESULTS: Preoperative HVA in patients with S- and SS-HV was significantly improved at the final follow-up (P < .0001 for both comparisons). No significant differences in postoperative HVA and IMA were observed between patients with S- and SS-HV (P = .51 and .50, respectively). All 5 preoperative subscale scores of SAFE-Q in patients with S- and SS-HV significantly improved postoperatively (P < .01 for all comparisons). Preoperative VAS-PS in patients with S- and SS-HV significantly improved postoperatively (P < .0001 and <.009, respectively). There were no significant differences in preoperative and postoperative scores of all the SAFE-Q subscales and VAS-PS between patients with S-HV and SS-HV (P > .10 for all) with the numbers available. CONCLUSION: We found for this patient group that a proximal supination osteotomy can achieve a large correction for SS-HV as well as S-HV and significantly improve radiologic and clinical outcomes in SS-HV. The outcomes between patients with S- and SS-HV were not different in this series. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Is just one screw really enough? Single- versus double-screw in the medial malleolus in supination-external rotation ankle fractures: A comparative biomechanical study using partially threaded cancellous screws.

OBJECTIVE: The aim of this study is to investigate stiffness and the maximum load to failure values of single- and double-screw fixation of oblique medial malleolus fractures using partially threaded cancellous screws. Our hypothesis is that single-screw fixation of medial malleolus fractures after SER injuries provides similar stiffness when compared with double-screw fixation. DESIGN: Biomechanical study. METHODS: Twelve composite polyurethane synthetic right distal tibiae were used in the experiment. Oblique fractures of the medial malleolus were created with a band saw using a custom-made osteotomy guide to standardize the cuts in all models. Bone models were randomly separated into two groups and fixed with one (n = 6) or two (n = 6) 4.0 mm partially threaded cancellous screws placed perpendicular to the fracture line. These were tested by applying an offset axial tension at 10 mm/minute up to maximum load displacement, defined as subsidence of the medial malleolus fragment. Maximum load to failure was determined for the groups at the point where the curve ceased to be linear and suffered an inflection. Force versus displacement curves were obtained and recorded. The student's t-test for independent samples was used to compare stiffness (N / mm) and maximum load (N) between experimental groups, with a p value of < 0.05. RESULTS: There were no significant differences in stiffness (p = 0.290) and maximum load (p = 0.191) among the two fixation constructs. Mean stiffness was 62.26 (±SD 21.11) N/mm for double-screw fixation group and 48.24 (±SD 22.40) N/mm for single-screw fixation group. Mean maximum load was 387.83 (±SD 115.78) N for double-screw fixation group and 306.64 (±SD 81.97) N for single-screw fixation group. CONCLUSION: Fixation with one 4.0 mm partially threaded cancellous screw was not shown to be biomechanically inferior to fixation with two 4.0 mm partially threaded cancellous screws in an oblique fracture of the medial malleolus, supporting previous clinical studies that have shown that one screw is sufficient for fractures of the medial malleolus.

Does a rupture of the lateral ankle ligament need to be repaired in supination-adduction type II (OTA/AO 44A2) fractures?

PURPOSE: To evaluate the outcomes of patients with supination-adduction (SAD) type II (OTA/AO 44A2) fractures who had a lateral ankle ligament rupture repaired compared with patients who did not have a lateral ankle ligament repaired using patients who underwent fibula fracture fixation as a control group. METHODS: A retrospective analysis of all 104 patients diagnosed with SAD type II fractures from January 2011 to December 2020 and managed operatively was performed. The patients were divided into three groups: 32 patients with ruptures of the lateral ligaments that were not repaired (group A), 34 patients with ruptures of the lateral ligaments that were repaired (group B), and 38 patients with fibula fracture fixation acting as the control group (group C). The objective outcomes including radiographic findings, the ankle range of motion, the manual ankle stress tests, and complications were gained from the record of the last time in outpatient clinics. The functional outcomes including the identification of functional ankle instability (IdFAI) scores were collected postoperatively at 12-month intervals to assess clinical outcomes. The Manchester Oxford Foot Questionnaire (MOXFQ) and Karlsson scoring scale were also recorded at the last follow-up. RESULTS: The mean follow-up of the objective and subjective functional outcomes was 23.4 (range, 13-42) and 76.9 (range, 25-134) months, respectively. There was no significant difference in the radiographic findings, the ankle range of motion and complications between the three groups. All ankles were found to be stable using the manual ankle stress test in both group A and group B. The IdFAI scores showed a significant difference between group A and group B (1.12 ± 1.3 vs 0.35 ± 0.69; p < 0.001) in the first year of follow-up and no significant difference after the first year. No differences were noted in MOXFQ scores or Karlsson scores among the groups. CONCLUSION: Directly repairing the lateral ligament could minimize the proportion of the first year of postoperative functional ankle instability, although the final stability of the ankle and clinical outcomes were not significantly different in SAD type II fractures. LEVEL OF EVIDENCE: Level III, retrospective comparative case series.

Supination resistance variations in foot and ankle musculoskeletal disorders: implications for diagnosis and customised interventions with wedged insoles.

BACKGROUND: Supination resistance is a clinical outcome that estimates the amount of external force required to supinate the foot. A greater supination resistance may indicate greater loads on structures responsible for generating internal supination moments across the subtalar joint during static and dynamic tasks. As such, greater supination resistance may be an expected finding in medial foot and ankle musculoskeletal disorders, such as plantar fasciopathy (PF) and posterior tibial tendon dysfunction (PTTD), whereas reduced supination resistance may be present in lateral ankle disorders, such as chronic ankle instability (CAI). However, no studies have yet investigated the changes in supination resistance across these foot and ankle musculoskeletal disorders. This study aimed to quantify supination resistance in individuals with PF, PTTD and CAI compared to healthy controls. Additionally, this study aimed to explore the changes in supination resistance following the simulation of varus and valgus wedges, which are commonly used interventions for these disorders. METHODS: Fourteen participants with PF, fourteen with PTTD, fourteen with CAI and fourteen healthy controls were recruited. Supination resistance was quantified on a level surface and on a 10-degree inclined surface with varus and valgus positions. RESULTS: Supination resistance was lower for the injured foot for CAI (p < 0.001) and greater for PTTD (p < 0.001) compared to the healthy foot. There was no significant between-foot difference observed for PF (p = 0.275) and controls (p = 0.970). In the injured foot, CAI exhibited lower supination resistance compared to controls (p < 0.001), PF (p = 0.012) and PTTD (p = 0.014). Regardless of the groups, supination resistance increased when tested on a surface with valgus inclination (p < 0.001) and decreased when tested on a surface with varus inclination (p < 0.001). CONCLUSIONS: Varus and valgus inclinations to the surface were effective in modifying supination resistance in PTTD and CAI, respectively. Supination resistance seemed unchanged in PF, and thus inclining the standing surface leads to greater between-feet asymmetries. This study also highlights the potential of wedged insoles as a mean to customise treatments and modify tissue stresses in these disorders. The findings contribute to the understanding of foot and ankle biomechanics and may aid in the development of more effective management and rehabilitation strategies.

Comparison of Supination-Adduction Type 2 and Supination-External Rotation Type 4 in Bimalleolar Ankle Fractures: Does Partial Pylon Variant of Supination-Adduction Type Fracture Affect Functional Outcomes?

BACKGROUND: Supination-adduction (SAD) type injuries are pylon variant injuries and lie between partial intra-articular pylon fractures and rotational ankle fractures. We aimed to evaluate functional outcomes of SAD type 2 bimalleolar fractures in comparison to supination-external rotation (SER) type 4 fractures. METHODS: We retrospectively reviewed data of 42 cases with SER type 4 and 20 cases with SAD type 2 injuries. Patients with a history of rheumatic disease, open fractures, pathologic fractures, nonbimalleolar fractures, neuropathic disease, and talus osteochondral lesion, and those operated on after greater than 72 hours because of skin lesion or managed with a two-stage surgical protocol after external fixation, were not included in the study. We compared these two groups in terms of the mean age, follow-up time, visual analog scale pain and American Orthopedic Foot and Ankle Society scores, Kellgren-Lawrence arthrosis classification, union time, and complications. RESULTS: The groups did not differ in terms of mean age (P = .115) and sex (P = .573). There was no significant difference in terms of union time between the groups (P = .686). American Orthopedic Foot and Ankle Society score was significantly higher in the SER group (91.2 ± 9.9) than in the SAD group (86.1 ± 13.2; P = .034). Visual analog scale pain scores were similar in the SAD (0.3 ± 0.92) and the SER (0.26 ± 0.7) groups (P = .897). CONCLUSIONS: Supination-adduction bimalleolar fractures may have worse functional outcomes in the intermediate term than do SER bimalleolar fractures, implying pylon variant fractures as a mechanism of injury. Supination-adduction bimalleolar fractures might be associated with a high rate of intra-articular cartilage impaction, resulting in varus deformity after surgery.

Surgical approach to forearm pronation deformity in patients with cerebral palsy: a systematic review.

Background: Pronation deformity in patients with cerebral palsy can have a major impact on upper limb functionality. There is lack of consensus in the literature about the preferred surgical technique to address this deformity. Study aim: To evaluate and synthesize the outcome of different surgical techniques for pronation deformity in patients with cerebral palsy. Methodology: The databases MEDLINE and Embase were searched for publications up to December 2021. Articles were considered eligible for inclusion when the included patients had a pronation deformity caused by cerebral palsy and results of surgical intervention for pronation deformity were examined. Evaluation of the quality of the retrieved study was conducted using the MINORS tool. Meta-analysis was not possible due to the heterogeneity of interventions and reported outcomes. Results: Nineteen studies, involving 475 patients and eight different techniques were included. All studies reported gain of active supination in most patients. The effect of surgery on functional gain was less clear and there was a large heterogeneity of reported functional outcome measures. There were 46 reported complications. Overall quality of study design was poor, illustrated by the average MINOR score of 6.9/16. Overall, there is a high risk of bias due to poor internal and external validity of the studies. Conclusion: Despite positive reports on gain in supination and functionality after most procedures addressing pronation deformity in CP patients, no conclusions can be drawn concerning the preferred technique due to the low quality of the evidence.

Covariation between wrist bone morphology and maximal range of motion during ulnar deviation and supination in extant nonhuman primate taxa.

This study investigates the maximal range of motion (ROM) during wrist deviation and forearm rotation for five different primate genera and the possible correlation with the shape of the distal ulna, triquetrum and hamate. A two-block phylogenetic partial least square analysis was performed to test this covariation in a phylogenetic context, using shape coordinates and a matrix of maximal ROM data as input data. The results show that gibbons have the highest ROM for both ulnar deviation and supination, whereas Macaca exhibited the lowest ROM for supination, and Pan had the lowest ROM for ulnar deviation. These results can be attributed to differences in locomotor behaviour, as gibbons need a large wrist mobility in all directions for their highly arboreal lifestyle, whereas Macaca and Pan need a stable wrist during terrestrial locomotion. However, we found no correlation between distal ulna/triquetrum/hamate shape and maximal ROM during ulnar deviation and supination in the different primate taxa. A larger dataset, in combination with behavioural and biomechanical studies, is needed to establish form-function relationships of the primate hand, which will aid the functional interpretation of primate fossil remains.

[Conservative treatment of supination and external rotation for type â ¢ and â £ankle fracture by bone setting].

OBJECTIVE: To explore curative effect of conservative treatment of supination-lateral rotation (SER) with type Ⅲ and Ⅳ ankle fracture by bone setting technique. METHODS: From January 2017 to December 2019, 64 patients diagnosed with SER with type Ⅲ and Ⅳ ankle fracture were treated with manipulative reduction and conservative treatment (manipulation group) and surgical treatment with open reduction and internal fixation (operation group), 32 patients in each group. In manipulation group, there were 17 males and 15 females, aged from 15 to 79 years old with an average of (51.42±13.68) years old;according to Lauge-Hansen classification, there were 8 patients with supination external rotation type Ⅲ and 24 patients with type Ⅳ. In operation group, there were 13 males and 19 females, aged from 18 to 76 years old with an average of (47.36±15.02) years old;7 patients with type Ⅲ and 25 patients with type Ⅳ. Displacement of ankle fracture was measured by Digimizer software, and compared before treatment, 3 and 12 months after treatment between two groups. Lateral medial malleolus displacement, lateral medial malleolus displacement, lateral malleolus displacement, lateral malleolus displacement, lateral malleolus contraction displacement and posterior malleolus displacement were measured and compared between two groups. Mazur score was used to evaluate ankle joint function. RESULTS: All patients were followed up from 12 to 36 months with an average of (17.16±9.36) months. There were statistical differences in lateral medial malleolus displacement, lateral medial malleolus displacement, lateral malleolus displacement, lateral malleolus displacement, lateral malleolus contraction displacement and posterior malleolus displacement in manipulation group before and after reduction(P<0.05). Compared with operation group, there were no statistically significant differences in lateral malleolus shift, lateral malleolus shift, lateral malleolus contraction shift(P>0.05), while there were statistically significant differences in lateral malleolus shift, posterior malleolus shift up and down (P<0.05). Mazur scores of ankle joint at 3 months after treatment in manipulation group and operation group were 68.84±13.08 and 82.53±7.31, respectively, and had statistical differences(P<0.05), while there was no difference in evaluation of clnical effect(P>0.05). There were no differences in Mazur score and evaluation of clnical effect between two groups at 12 months after treatment (P>0.05). CONCLUSION: Bone setting technique could effectively correct lateral displacement of medial malleolus, lateral displacement of medial malleolus, lateral displacement of lateral malleolus and lateral contraction displacement of lateral malleolus in supination lateral rotation type Ⅲ and Ⅳ ankle fracture, and has good long-term clinical effect, which could avoid operation for some patients and restore ankle function after fracture.

Deep branch of the radial nerve: effect of pronation/supination on longitudinal nerve alignment.

OBJECTIVE: To evaluate the effect of maximal pronation and supination of the forearm on the alignment and anatomic relationship of the deep branch of the radial nerve (DBRN) at the superior arcade of the supinator muscle (SASM) by using high-resolution ultrasound (HRUS). MATERIALS AND METHODS: In this cross-sectional study, HRUS in the long axis of the DBRN was performed in asymptomatic participants enrolled from March to August 2021. DBRN alignment was evaluated by measuring angles of the nerve in maximal pronation and maximal supination of the forearm independently by two musculoskeletal radiologists. Forearm range of motion and biometric measurements were recorded. Student t, Shapiro-Wilk, Pearson correlation, reliability analyses, and Kruskal-Wallis test were used. RESULTS: The study population included 110 nerves from 55 asymptomatic participants (median age, 37.0 years; age range, 16-63 years; 29 [52.7%] women). There was a statistically significant difference between the DBRN angle in maximal supination and maximal pronation (Reader 1: 95% CI: 5.74, 8.21, p < 0.001, and Reader 2: 95% CI: 5.82, 8.37, p < 0.001). The mean difference between the angles in maximal supination and maximal pronation was approximately 7° for both readers. ICC was very good for intraobserver agreement (Reader1: r ≥ 0.92, p < 0.001; Reader 2: r ≥ 0.93, p < 0.001), as well as for interobserver agreement (phase 1: r ≥ 0.87, p < 0.001; phase 2: r ≥ 0.90, p < 0.001). CONCLUSION: The extremes of the rotational movement of the forearm affect the longitudinal morphology and anatomic relationships of the DBRN, primarily demonstrating the convergence of the nerve towards the SASM in maximal pronation and divergence in maximal supination.

Comparison of different treatment methods for supination-lateral rotation ankle fractures.

OBJECTIVES: This study aims to compare the therapeutic effects of fixation with fibular approach, fixation with posterolateral fibular approach, and conservative therapy on supination-lateral rotation ankle fractures. PATIENTS AND METHODS: A total of 189 patients (103 males, 86 females; mean age: 45.7±4.7 years; range, 40 to 51 years) with supination-lateral rotation ankle fractures treated in our hospital between March 2020 and March 2021 were included in this prospective study. The patients were assigned into conservative therapy, fibular approach, and posterolateral approach groups including 63 patients in each group. Clinical conservative therapy was performed for conservative therapy group, while fibular approach and posterolateral approach groups were given fixation with fibular approach and posterolateral fibular approach, respectively. Their routine parameters, body stress, ankle function, treatment efficacy and safety were compared. RESULTS: The length of hospital stay was shorter in the fibular approach and posterolateral approach groups than the conservative therapy group, particularly in the fibular approach group (p<0.05). The pain stress and oxidative stress were lower in the fibular approach and posterolateral approach groups than the conservative therapy group, particularly in the posterolateral approach group (p<0.05). Compared to the conservative therapy group, the fibular approach and posterolateral approach groups had significantly recovered ankle function, with better recovery in the posterolateral approach group (p<0.05). The response rate was higher in the fibular approach and posterolateral approach groups than the conservative therapy group, being higher in the posterolateral approach group (p<0.05). CONCLUSION: For patients with supination-lateral rotation ankle fractures, fixation with posterolateral fibular approach is more effective for expediting the recovery of ankle joints than conservative therapy and fixation with fibular approach, accompanied by higher safety.

Can we safely place the distal volar locking plate screws into the subchondral zone of a distal radius fracture using a 45° supination oblique view under fluoroscopic guidance?

INTRODUCTION: Careful distal locking screw insertion into the subchondral zone is necessary to obtain proper mechanical strength of unstable distal radius fractures using volar locking plating. However, subchondral zone screw insertion increases the risk of intra-articular screw penetration, which may remain unrecognized during surgery due to complex distal radial anatomy. The purpose of this study was to evaluate the role of fluoroscopic guidance with a 45° supination oblique view technique for placing distal screws into the subchondral zone during volar locking plating for unstable distal radius fractures and to explore the factors associated with poor screw placement. METHODS: We retrospectively analyzed 171 wrists of 169 patients treated with variable-angle volar locking plates for unstable radius fractures. The subchondral zone was defined as the metaphyseal area within 4 mm of the articular margin of the distal radius. The location of the distal locking screws and radiographic parameters, including the teardrop angle, were measured using computed tomography scans and X-rays. Clinical and radiographic factors were examined to determine their possible associations with screw placement failure. RESULTS: Of 581 distal screws inserted, 559 screws (96.2%) were inserted into the subchondral zone and 17 screws into the metaphyseal zone (2.9%). Five screws (0.7%) in three wrists showed intra-articular placement: four screws were placed into the lunate fossa and one into the scaphoid fossa. These three wrists also exhibited significantly reduced teardrop angles. The distal screws were significantly closer to the joint line in the lunate fossa than the scaphoid fossa (1.9 ± 0.9 mm vs. 2.8 ± 1 mm, P < 0.000). CONCLUSION: The 45° supination oblique view technique is a useful fluoroscopic guiding technique for accurate and safe distal screw placement in the subchondral zone in volar locking plate fixation for distal radial fractures. However, a decreased teardrop angle or extended lunate fossa should be corrected before distal screw insertion to avoid intra-articular screw placement.

Malunion deformity of the forearm: Three-dimensional length variation of interosseous membrane and bone collision.

It remains unclear to what extent the interosseous membrane (IOM) is affected through the whole range of motion (ROM) in posttraumatic deformities of the forearm. The purpose of this study is to describe the ligament- and bone-related factors involved in rotational deficit of the forearm. Through three-dimensional (3D) kinematic simulations on one cadaveric forearm, angular deformities of 5° in four directions (flexion, extension, valgus, varus) were produced at two locations of the radius and the ulna (proximal and distal third). The occurrence of bone collision in pronation and the linear length variation of six parts of the IOM through the whole ROM were compared between the 32 types of forearm deformities. Similar patterns could be observed among four groups: 12 types of deformity presented increased bone collision in pronation, 8 presented an improvement of bone collision with an increase of the mean linear lengthening of the IOM in neutral rotation, 6 had an increased linear lengthening of the IOM in supination with nearly unchanged bone collision in pronation and 6 types presented nearly unchanged bone collision in pronation with a shortening of the mean linear length of IOM in supination or neutral rotation. This kinematic analysis provides a better understanding of the ligament- and bone-related factors expected to cause rotational deficit in forearm deformity and may help to refine the surgical indications of patient-specific corrective osteotomy.

Long-Term Outcomes of Biceps Rerouting for Flexible Supination Contractures in Children With Brachial Plexus Birth Injuries.

PURPOSE: Forearm supination contractures occur in 7% of children with brachial plexus birth injuries (BPBI). Biceps rerouting is proposed when pronation has deteriorated but is passively correctable to at least 0° (neutral). The purpose of this investigation was to evaluate long-term outcomes of biceps rerouting for this indication, including magnitude and maintenance of correction, complications, and subsequent osteotomy. METHODS: We conducted a retrospective review of all children with BPBI and forearm supination contractures treated with biceps rerouting alone, for the above indications, from 1993 to 2017 with at least 2 years follow-up. Demographic information, BPBI characteristics, surgical details, and ranges of motion were obtained from medical records. Pre- and postoperative active pronation (AP) and supination (AS), elbow flexion contracture, and arc of forearm rotation (Arc) were analyzed using linear mixed-effect models. RESULTS: Twenty-five children (13 females; 13 left forearms; 15 global BPBI) underwent biceps rerouting at age 7 ± 3 years and were followed for 6 ± 3 years. Before surgery, the mean AP and AS were 6° ± 29° and 62° ± 27°, respectively. At the final follow-up, the mean AP, AS, and Arc were 39° ± 36°, 18° ± 34°, and 57° ± 42°, respectively. AP was significantly improved and AS was significantly decreased by 2 years after surgery and at the final follow-up. Neither Arc nor elbow flexion contracture changed significantly. Two of 25 (8%) children underwent subsequent forearm osteotomy. CONCLUSIONS: Biceps rerouting in children with BPBI improves the forearm position when pronation is deteriorating by shifting the arc from supination to pronation without decreasing the arc of motion or worsening elbow flexion contractures. There is a low risk of complications and a limited need for subsequent forearm osteotomy. These results are maintained over time. When performed before passive pronation is reduced beyond neutral, this procedure may prevent severe supination contractures and reduce the need for forearm osteotomy. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

The effects of maximal radial bowing on forearm rotation in pediatric diaphyseal forearm fractures.

PURPOSE: To evaluate the effects of radial bowing on forearm rotation in forearm fractures compared with healthy children. METHODS: A retrospective study was conducted on children aged 1-16 years old. Group 1 was children with history of diaphyseal forearm fractures, and group 2 was healthy children. Children in group 1 with ≤ 70° forearm pronation and/or ≤ 80° supination on affected side are defined as "case." In group 2, children with forearm pronation > 70° and/or supination > 80° are defined as "control." Radial bowing was measured on AP radiograph of the forearm; maximal radial bowing (MRB) and location of the maximal radial bowing (LMRB) were recorded. RESULTS: Total of 112 children were included (group 1 = 70, group 2 = 42). In group 1, there were 28 children with ≤ 70° forearm pronation and/or ≤ 80° forearm supination (case group). In group 2, there were 33 children with > 70° forearm pronation and > 80° forearm supination (control group). Mean age of case and control group was 11.08 ± 3.02 and 7.85 ± 3.93 years, respectively. Average MRB was 6.15 ± 1.93% and LMRB was 61.94 ± 9.41% in case group. In control group, average MRB was 7.23 ± 1.03% and LMRB was 62.08 ± 4.24%. There was statistically significant correlation between children with ≤ 70° forearm pronation and MRB (P = 0.034) compared with control group. Also, there was statistically significant correlation between children with ≤ 80° forearm supination and MRB (P = 0.023) compared with control group. For ROC curve analysis, MRB ≤ 6.84% showed the association with ≤ 70° forearm pronation (72.2% sensitivity and 73.8% specificity) and MRB ≤ 5.75% associated with ≤ 80° forearm supination (54.6% sensitivity and 84.9% specificity). CONCLUSIONS: Children with MRB ≤ 6.84% can result in ≤ 70° forearm pronation, and MRB ≤ 5.75% can be presented with ≤ 80° forearm supination.

Preoperative radius head dislocation affects forearm rotation after mobilization of congenital radioulnar synostosis.

BACKGROUND: The present study was carried out to answer three questions: 1) How much forearm rotation can be expected after mobilization of congenital radioulnar synostosis (CRUS)? 2) Does preoperative radius head dislocation affect forearm rotation after mobilization? 3) What factors other than radius head dislocation affect postoperative forearm rotation? METHODS: We performed mobilization of CRUS with a free vascularized fascio-fat graft and a radius osteotomy (Kanaya's procedure) on 26 forearms of 25 patients. The age at the surgery ranged from 5.3 to 13.4 years. The follow-up duration ranged 24-111 months. We classified CRUS into 3 groups according to the dislocation of the radius head: posterior dislocation (N = 13), anterior dislocation (N = 9) and no dislocation (N = 4). Since major complaints of patients and parents were poor forearm rotation and lack of supination, they were evaluated separately. RESULTS: Mean preoperative forearm ankylosis angle was 34.8° (range; neutral to 90° pronation). Preoperative pronation ankylosis angle was higher in the posterior dislocation group (mean 55.3°) than the anterior dislocation (mean 11.6°) and no dislocation groups (mean 5.0°). There was no re-ankylosis after mobilization and the mean postoperative active range of motion (ROM) was 86.5°. The mean active ROM was 75.7° in the posterior dislocation group, 96.1° in anterior dislocation group and 100.0° in no dislocation group. The mean active supination was 6.9, 33.9 and 47.5° respectively. The posterior dislocation group showed less ROM and less supination than other groups. Preoperative pronation ankylosis angle showed negative correlation with postoperative ROM (ρ = - 0.59) and postoperative supination (ρ = - 0.73). CONCLUSION: The mean postoperative active ROM of this mobilization was 86.5°. Posterior dislocation group showed higher pronation ankylosis angle preoperatively, and less postoperative ROM and less supination than anterior and no dislocation groups. Preoperative pronation ankylosis angle showed negative correlation with postoperative ROM and supination.

Kinematic analysis of forearm rotation using four-dimensional computed tomography.

This study aimed to quantify forearm kinematics with a focus on the forearm rotation axis. Ten healthy volunteers were included in the study. One three-dimensional computed tomographic scan and two four-dimensional computed tomographic scans were done in all the arms to capture forearm joint motion. After image processing, the rotation axis and the movement of the radius with respect to various axes were quantified. The rotation axis was calculated using finite helical axis analysis and a circle fitting approach. The mean error of the rotation axis found through circle fitting was 0.2 mm (SD 0.1) distally and 0.1 mm (SD 0.1) proximally, indicating an improvement in precision over the finite helical axis approach. The translations of the radius along the ulnar axis and the forearm rotation axis were 2.6 (SD 0.8) and 0.6 mm (SD 0.9), respectively. The rotation of the radius around the radial axis was 7.2°. The techniques presented provide a detailed description of forearm kinematics.