Active Forearm Rotation Research Articles

'Switch' technique to restore pronation and radial deviation in 17 patients with brachial plexus birth palsy.

We report outcomes of 17 children with brachial plexus birth palsy that underwent extensor carpi ulnaris to brachioradialis and brachioradialis to abductor pollicis longus transfers to correct supination and ulnar deviation deformity. Mean age at the time of surgery was 8.7 years and mean follow-up time was 21 months (8-44). These patients had marked increases in active forearm rotation and Canadian Occupational Performance Measure scores. Activity performance score on the measure increased from 1.1 to 6.7 and satisfaction score increased from 0.8 to 8.7 at final follow-up. We conclude from our patient series that these tendon transfers are effective in correction of the supination and ulnar deviation deformities in brachial plexus birth palsy. Level of evidence: IV.

Effect of Radial Head Implant Shape on Radiocapitellar Joint Congruency

Radial head arthroplasty is indicated in displaced fractures in which comminution precludes successful internal fixation. Many types of radial head implants have been developed varying in material, methods of fixation, and degrees of modularity and geometry. The purpose of this study was to investigate the effect of radial head implant shape on radiocapitellar joint congruency. Joint congruency was quantified in 7 cadaveric specimens employing a registration and inter-surface distance algorithm and 3-dimensional models obtained using computed tomography. Forearm rotation was simulated after computer-guided implantation of an axisymmetric radial head, a population-based quasi-anatomic radial head implant, and a reverse-engineered anatomic radial head implant. Inter-surface distances were measured to investigate the relative position of the radial head implant and displayed on 3-dimensional color-contour maps. Surface area was measured for inter-surface distances (1.5 mm) and compared for each radial head geometry. There were no statistical differences in the contact surface area between radial head implants during active or passive forearm rotation. The joint was more congruent (larger contact surface area) during active forearm rotation compared with passive forearm rotation. This study investigated the effect of implant geometry on the radiocapitellar joint contact mechanics by examining a commercially available radial head system (axisymmetric), a quasi-anatomic design, and an anatomic reverse-engineered radial head implant. We found no statistical differences in radiocapitellar joint contact mechanics as measured by 3-dimensional joint congruency in cadaveric specimens undergoing continuous simulated forearm rotation. The importance of choosing an implant that matches the general size of the native radial head is recognized, but the degree to which it is necessary to create an implant that replicates the native anatomy to restore elbow stability and prevent cartilage degenerative changes remains unclear. This study concluded that the geometry of the implant did not have a statistically significant effect on joint contact mechanics; therefore, future work is needed to examine additional factors related to implant design, such as material choice and implant positioning to investigate their influence on joint contact mechanics.

Mobilization of a Congenital Proximal Radioulnar Synostosis with a Vascularized Fascio-fat Graft in 104 Forearms of 87 Patients: Level 4 Evidence

There is no financial information to disclose. Congenital proximal radioulnar synostosis is a rare congenital anomaly characterized by a fixed forearm rotation. It has the high tendency toward re-ankylosis after separation without interposition between separated radius and ulna. Can the congenital radioulnar synostosis be mobilized? If so, what is the safe and simple procedure for mobilization? We performed mobilization procedures for 104 forearms in 87 patients. Through a posterior incision, the synostosis was exposed and separated with a high-speed burr. After separation, osteotomy of the radius was performed to reduce the dislocated radius head. After that, a vascularized fascio-fat was interposed between separated radius and ulna. Four different procedures were used to interpose the vascularized fat. A free vascularized fascio-fat graft (FVFG) was used in 26 forearms, a pedicle forearm fascio-fat graft with one incision (PVFG-1) in 25, a pedicle forearm fascio-fat graft with both anterior and posterior incisions (PVFG-2) in 26, and a pedicle upperarm fascio-fat graft in two incisions (PVFG-3) in 27. The mean age at the surgery was 8.1 years (range, 5.1 to 13 years), 7.4 years (range, 4.3 to 10.9 years), 7.8 years (range, 4 to 14 years) and 6.0 years (range 4.5 to 6.0) respectively. Preoperative forearm ankylosis was 34.8 degrees of pronation in FVFG, 39.3 degrees in PVFG-1, 40.2 degrees in PVFG-2, and 37.4 degrees in PVFG-3. They were followed-up more than 2 years after surgery. All patients reported improvements in performing some activities, such as catching a ball, accepting objects such as coins, holding a bowl of soup, and performing gymnastics. Four re-ankyloses were observed among 104 mobilizations. The mean range of active forearm rotation (mean ± SD) after mobilization was 81.6 ± 15.8 degrees in FVFG, 75.4 ± 23 degrees in PVFG-1 excluding 3 re-ankyloses, 71.1 ± 27.4 degrees in PVFG-2, and 70.2 ± 25.4 degrees in PVFG-3 excluding 1 re-ankylosis. The average surgery time was 9.8 ± 0.79 hours in FVFG, 4.3 ± 2.0 hours in PVFG-1, 3.9 ± 1.3 hours in PVFG-2, and 4.2 ± 1.7 hours in PVFG-3. •This mobilization procedure prevented re-ankylosis after separation of the synostosis and provided some forearm rotation that improved a child's daily activities.•Mobilization with a pedicle fascio-fat graft shortened the surgery time than those with free vascularized fascia-fat graft.•Two-incision technique could securely fasten PVFG to the space between separated radius and ulna and may prevent re-ankylosis.

Effect of Volarly Angulated Distal Radius Fractures on Forearm Rotation and Distal Radioulnar Joint Kinematics

To examine the effect of volar angulation deformities of the distal radius with and without triangular fibrocartilage complex (TFCC) rupture on forearm range of motion and the kinematics of the ulnar head at the distal radioulnar joint (DRUJ) during simulated active forearm rotation. Volar angulation deformities of the distal radius with 10° and 20° angulation from the native orientation were created in 8 cadaveric specimens using an adjustable apparatus. Active supination and pronation were performed using a forearm motion simulator. Pronation and supination range of motion was quantified with each deformity. In addition, changes in the dorsovolar position of the ulnar head relative to the radius were calculated after simulating each distal radial deformity. Testing was performed with the TFCC intact and sectioned. Volar angulation deformities of 20° decreased the supination range with preservation of pronation. There was no effect of TFCC status on the range of forearm rotation. With the TFCC intact, volar angulation deformities translated the ulna slightly dorsally in pronation and volarly in supination. After sectioning the TFCC, volar angulation deformities of 10° and 20° translated the ulna dorsally throughout forearm rotation. Volar angulation deformities reduce supination range and alter the DRUJ kinematics. The increased tension in the intact TFCC caused by volar angulation deformities likely prevented the expected dorsovolar displacement at the DRUJ and restricted supination. Dividing the TFCC released the constraining effect on the DRUJ and allowed the ulna to translate dorsally. However, supination remained limited, presumably because of impediment from the dorsally subluxated ulna. This study demonstrated the importance of correcting volar angulation deformities of the distal radius to less than 20° in order to maintain normal range of forearm rotation and to less than 10° to maintain normal DRUJ kinematics when the TFCC is ruptured.

Volar subluxation of the ulnar head in dorsal translation deformities of distal radius fractures: an in vitro biomechanical study.

To quantify the effects of dorsal translation deformities of the distal radius with and without dorsal angulation on volar displacement of the ulnar head during simulated active forearm rotation, both with the triangular fibrocartilage complex (TFCC) intact and sectioned conditions. Eight fresh-frozen cadaveric upper extremities were mounted in an active forearm motion simulator, and distal radial deformities of 0, 5, and 10 mm of dorsal translation with 0, 10, 20, and 30 degrees of dorsal angulation were simulated. Volar displacement of the ulnar head at the distal radioulnar joint as a result of each distal radial deformity was quantified during simulated active supination. The data were collected with the TFCC intact and after sectioning the TFCC at its ulnar insertion. Increasing isolated dorsal translation deformities increased volar displacement of the ulnar head when the TFCC was intact (P < 0.001). Increasing dorsal translation combined with dorsal angulation increased volar displacement of the ulnar head compared with isolated dorsal angulation deformities (P < 0.001). Sectioning the TFCC increased the volar displacement of the ulnar head caused by each distal radial deformity (P = 0.001). These results emphasize the clinical importance of evaluating the magnitude of both dorsal translation and dorsal angulation when managing displaced distal radius fractures and malunions.

Anatomy and Biomechanics of the Forearm Interosseous Membrane

To examine the anatomy and function of the forearm interosseous membrane by exploring the anatomical insertions of the central band (CB) on the radius and the ulna and by quantifying the length of the intact ligament and replacement grafts located at the original CB attachment sites and alternative locations. Eight fresh cadaver forearms were supinated and pronated and the wrist was extended and flexed while the motion between the distal radius and ulna were recorded. The length of the CB was computed for the intact CB as well for several alternative graft orientations and positions. The maximum length of the CB did not significantly change among different wrist motions. However, with the wrist in a static neutral position, the CB length was significantly shorter in forearm supination than in neutral. During active forearm rotation when CB replacement grafts were positioned distal or proximal to the original CB site, yet still parallel to it, each had a similar trend to be longer in neutral than in supination. If a graft was more transversely oriented, the computed CB length would be 1.6 mm shorter in supination than in neutral. These results support tensioning a CB graft with the forearm in supination if the goal is to maximize graft tension and to maintain the native 22° angle for a CB graft between the radius and ulna. The results also suggest that the CB graft can probably be located slightly distal or slightly proximal to its original attachment sites. Reconstruction of the interosseous membrane has been hampered by a lack of understanding of its length changes with forearm or wrist motion. These results provide a starting point in helping clinicians understand how to more precisely reconstruct this ligament in an anatomical manner.

Distal Radioulnar Joint Kinematics in Simulated Dorsally Angulated Distal Radius Fractures

To examine the effects of dorsal angulation deformities of the distal radius with and without triangular fibrocartilage complex (TFCC) rupture on the 3-dimensional kinematics of the distal radioulnar joint (DRUJ) during simulated active motion. Nine fresh-frozen cadaveric specimens were tested in a forearm simulator that produced active forearm rotation. Dorsal angulation deformities of the distal radius with 10°, 20°, and 30° angulation were created. Changes in the position of the ulna relative to the radius at the DRUJ as a consequence of each dorsal angulation deformity were quantified during simulated active supination in terms of volar, ulnar, and distal displacement of the ulna. Testing was performed initially with the TFCC intact and repeated after complete sectioning of the TFCC at its ulnar insertion. Increasing dorsal angulation deformities of the distal radius significantly increased volar, ulnar, and distal displacement of the ulna when the TFCC was intact. Sectioning of the TFCC significantly increased volar displacement of the ulna in dorsal angulation deformities. As little as 10° of dorsal angulation significantly increased distal displacement of the ulna with the TFCC intact and resulted in a significant increase in volar, ulnar, and distal displacement of the ulna with sectioned TFCC. Dorsal angulation deformities of the distal radius affect the 3-dimensional kinematics of the DRUJ, especially with the TFCC sectioned. The progressive change in DRUJ kinematics with increasing dorsal angulation may partially explain the relationship between the magnitude of dorsal angulation of distal radius fractures and functional outcomes in younger patients. The status of the TFCC should be evaluated carefully, as well as the magnitude of osseous deformity in patients with distal radius fractures and malunions, because changes in DRUJ kinematics caused by dorsal angulation are greater when the TFCC is ruptured.

The Effect of Short Arm Cast Length on Forearm Rotation

To compare ranges of active forearm pronation and supination with subjects wearing short arm casts of different lengths. Forty right-handed healthy volunteers (20 men and 20 women) with an average age of 39 years (range, 26-58 y) were recruited. A goniometer with a circular plate and a handle connected to the scale indicator was used to measure forearm pronation and supination without a cast and with 3 different lengths of short arm cast. All casts extended from just proximal to the volar and dorsal aspects of metacarpophalangeal joints, and continued to either 2.5 cm distal to elbow flexion crease or 5 cm distal to the elbow flexion crease, or to the proximal one-third position between the wrist flexion crease and the elbow flexion crease. Compared with no immobilization, the longest of the 3 constructs reduced active forearm rotation by 62%, whereas the cast to 5 cm from the elbow flexion crease reduced rotation to 50%, and the cast to the proximal one third of the way between the wrist and elbow flexion crease reduced rotation by 32%. Active forearm rotation was significantly dependent on cast length, and reductions in active forearm rotation were positively correlated with cast length. Limitation of active forearm rotation by a short arm cast is positively correlated with cast length. When a short arm cast is used to limit wrist motion and forearm rotation, it is better to extend it proximally but not to impinge on the antecubital fossa, where skin breakdown may occur.

Wrist Tendon Forces With Respect to Forearm Rotation

Early motion therapy protocols are desirable to reduce wrist stiffness after carpal injuries and distal radius fractures. Based on our assumption that a reduction in wrist tendon forces will be associated with a reduction in radioulnar carpal joint reaction force, the goal of this study was to determine the forearm position at which the wrist tendon forces required to initiate wrist motion were the least. We tested 8 fresh-frozen cadaver forearms in a wrist and forearm motion simulator. In each specimen, we generated a wrist flexion-extension motion and a radioulnar deviation motion by pulling on the wrist flexor and extensor tendons with the forearm in supination, pronation, or neutral. We also performed a wrist flexion-extension motion during active forearm rotation. During each motion, we continuously recorded the forces in the 5 wrist tendons. We used repeated-measure analyses of variance to compare tendon forces. During the wrist flexion-extension motion, the summed peak wrist extensor forces were significantly less with the wrist in forearm supination than with the forearm in neutral or during active forearm rotation. For the summed peak wrist flexor forces, flexor tendon forces were significantly less with the forearm in supination compared with active forearm rotation. The extensor carpi radialis longus and flexor carpi ulnaris forces were significantly less in supination than during active forearm motion. During wrist radioulnar deviation motion, peak extensor carpi ulnaris force was significantly less with the forearm in supination than in neutral, and peak flexor carpi radialis force was significantly less with the forearm in supination than in pronation. Peak wrist tendon forces were least in the static forearm supinated position. To reduce deforming forces on a fresh carpal injury or distal radial fracture, active rehabilitation appears to be best initiated with the forearm held in supination.

Comparison of Forearm Rotation Allowed by Different Types of Upper Extremity Immobilization

The purpose of this study was to compare the active forearm pronation and supination allowed by a short arm splint, short arm cast, sugar tong splint, long arm splint, and long arm cast in normal, healthy subjects. Forty healthy, right-handed volunteers (twenty men and twenty women) with a mean age of thirty-five years (range, twenty-three to sixty-six years) were recruited. Two examiners used a goniometer developed for the study to measure the active forearm supination and pronation in each subject with and without the application of the different types of upper extremity immobilization. Forearm pronation and supination were compared among the immobilization methods and between men and women. The inter-rater reliability of the measurements was evaluated with use of the intraclass correlation coefficient. The long arm cast decreased active forearm rotation to <10% of the value with no immobilization. The short arm cast, sugar tong splint, and long arm splint decreased active forearm rotation to <40% of the baseline measurement. No significant difference in active forearm supination or pronation was observed among the short arm cast, sugar tong splint, and long arm splint in the overall study cohort or in the men. However, forearm supination and pronation in the women differed significantly between the short arm cast and both the sugar tong splint and the long arm splint. The long arm cast provided the greatest restriction of forearm rotation. Overall, no significant difference in active forearm supination or pronation was observed among the short arm cast, sugar tong splint, and long arm splint.

2.4 mm anatomical locking compression plate for treatment of type C distal radius fractures in elderly patients

Objective To evaluate clinical outcomes of the elderly patients with type C distal radius fractures caused by osteoporosis who were treated by open reduction and internal fixation with 2.4 mm anatomical locking compression plate (LCP). Methods From October 2006 to November 2008, 21 elderly patients with comminuted unstable distal radius fractures caused by osteoporosis were treated by open reduction and internal fixation with 2. 4 mm LCP. They were 7 males and 14 females, with an average age of 76 years (range, 71 to 85 years). According to AO classification, there were 6 cases of type CI, 13 cases of type C2 and 2 cases of type C3. All of them were closed fractures of distal radius. All the fractures were fixed with 2.4 mm LCP by volar approach and dorsal soft tissues were not dissected during the operation. Artificial bones were implanted when the defects were large enough. Results The patients were followed up for 8 to 27 months (average, 10. 6 months) . The X-ray pictures showed primary union in all patients in a mean healing time of 8 weeks. Artificial bones were implanted in 2 cases. No infection, non-union, loosening of nails or carpal tunnel syndrome was found. Functional recovery was achieved in 4 to 36 weeks (average, 11 weeks) . Passive wrist motion, active finger motion and forearm rotation were encouraged immediately after surgery. Active wrist motion was suggested by 7 days postoperatively. The clinical outcomes were evaluated according to the modified Mcbide grading system. There were 14 excellent, 5 good and 2 fair cases, with a good-to-excellent rate of 90. 5%. Conclusion In treatment of unstable distal radius fractures caused by osteoporosis in elderly patients, the 2.4 mm LCP can result in a rigid fixation, early exercise, and an excellent clinical outcome. Key words: Radius fractures; Fracture fixation, internal; Plate

Movement patterns of the upper extremity and trunk associated with impaired forearm rotation in patients with hemiplegic cerebral palsy compared to healthy controls

The aim of this study was to objectively assess the relationship between impaired forearm rotation and movement patterns of the upper arm and trunk in patients with hemiplegic cerebral palsy. For this purpose, ‘extrinsic forearm rotation’ was introduced as a parameter to quantify the cumulative result of all movements that supplement forearm rotation. The results of three-dimensional video analysis of the upper extremity and trunk in different reaching tasks in eight male and two female patients (mean age, 16 years and 2 months) were compared to those of 10 case-matched controls. The active forearm rotation impairment in the patient group as compared to the controls was combined with a significantly higher value for ‘extrinsic forearm rotation’. In this way, we objectively measured compensatory movement patterns associated with impaired forearm rotation and, consequently, we advocate assessment of the overall movement strategy rather than just the forearm deformity in patients with hemiplegic cerebral palsy.

Comparison of Distal Radioulnar Joint Reconstructions Using an Active Joint Motion Simulator

Distal radioulnar joint (DRUJ) instability can result in pain and functional disability. Numerous DRUJ reconstructive options have been described with minimal biomechanical analysis. The purpose of this study was to evaluate the ability of 4 well-described DRUJ reconstructions to restore joint kinematics using a dynamic, motion-controlled simulator. Eleven cadaveric upper extremities had computer-controlled simulated active forearm rotation. Joint kinematics were quantified by using an electromagnetic tracking system. We compared the passive and simulated active kinematics of the intact, unstable, and reconstructed DRUJ (capsular repair, 2 described radioulnar ligament reconstructions, and a radioulnar tethering procedure). All reconstructions improved significantly the kinematics of the unstable DRUJ. The capsule repair restored simulated active joint kinematics closest to the intact DRUJ. All 4 reconstructions improved DRUJ stability significantly. The capsule repair most closely matched intact DRUJ kinematics and the radioulnar ligament reconstructions were found to be superior to a radioulnar tethering procedure.

Soft-tissue stabilizers of the distal radioulnar joint: an in vitro kinematic study

Purpose Distal radioulnar joint (DRUJ) stability is dependent on osseous anatomy, soft-tissue stabilizers, and muscle activity. The relative importance of DRUJ soft-tissue stabilizers remains controversial and has not been examined in the more physiologic setting of simulated muscle loading in the intact specimen. The purpose of this study was to examine the role of static stabilizers on the kinematics of the DRUJ during active simulated motion. Methods Twelve cadaveric upper extremities underwent computer-controlled, simulated, active forearm rotation. Joint kinematics were measured in the intact specimen and after sequential sectioning of soft-tissue stabilizers including the dorsal and palmar radioulnar ligaments (RULs) and the triangular fibrocartilage (TFC), dorsal and palmar capsule, ulnocarpal ligaments (UCL), extensor carpi ulnaris (ECU) subsheath, pronator quadratus (PQ), and the interosseous membrane (IOM). Results After sectioning of soft tissues significant changes in the DRUJ kinematics were observed. With a distal to proximal sectioning sequence significant alterations in kinematics were not identified until sectioning of the IOM; with a proximal to distal sectioning sequence intact DRUJ kinematics were maintained until the final soft-tissue (RULs and TFC) sectioning. Conclusions Sectioning of all soft-tissue stabilizers produced significant DRUJ instability and abnormal joint kinematics. The RULs and TFC play a key role in DRUJ kinematics because they can help to maintain normal joint rotation in the absence of all other soft-tissue stabilizers. With the preservation of other soft-tissue stabilizers, however, the RULs and TFC are not essential for the maintenance of normal kinematics of the DRUJ.

A surgical technique for pediatric forearm pronation: brachioradialis rerouting with interosseous membrane release

Purpose In this study we used a tendon transfer technique (consisting of rerouting of the brachioradialis with interosseous membrane release) to restore active forearm pronation in patients with supination deformity secondary to brachial plexus birth palsy. Methods Four children (3 with flexible supination deformities, 1 with a fixed supination deformity) whose ages ranged between 5 and 9 years had brachioradialis rerouting with interosseous membrane release. Results Mean active forearm rotation was improved from 28° supination before surgery to 49° pronation after surgery. No patient developed elbow contracture during a minimum of 12 months of follow-up evaluation (40 months in 2 patients, 14 months in 1 patient, 12 months in 1 patient). Conclusions These results suggest that brachioradialis rerouting combined with interosseous membrane release may be a successful means to correct supination deformity of the forearm.

Kinematics of ulnar head arthroplasty

This in vitro study evaluated the performance of an ulnar head replacement. A joint simulator was employed that produced active forearm rotation in cadaveric specimens, with motion measured using an electromagnetic tracking system. The kinematics of the intact forearm were compared with a partial ulnar head replacement and a full replacement (with and without soft-tissue reconstruction) and a full excision of the ulnar head. There were no differences between intact kinematics and those following prosthetic reconstruction. However, ulnar head excision produced distal radioulnar joint instability in the form of radioulnar convergence and increased anteroposterior translations.

The “Terrible Triad” of the Elbow

The “Terrible Triad” of the Elbow

SURGICAL CORRECTION OF SUPINATION DEFORMITY IN CHILDREN WITH OBSTETRIC BRACHIAL PLEXUS PALSY

We present a series of 40 children who were operated on for supination contracture following severe obstetric brachial plexus palsy. Surgery was done at an average age of 7 years and the mean postoperative follow-up was 4 years. In the 23 cases treated by an open or closed radial osteotomy, the mean intraoperative derotation was 78°, the immediate postoperative position was 29° pronation and it stabilized at follow-up at 17° pronation. Biceps rerouting was performed in 17 cases without any recurrence of supination deformity and the final position was 22° pronation. Some active forearm rotation was obtained in a few cases. These surgical corrections are part of an overall treatment plan and allow the “begging hand” to be corrected to a more functional and less noticeable position.