Introduction Loss of radius either due to trauma or infection results in a deformity resembling a congenital radial club hand. This deformity results in difficulty to perform hand functions and cosmetic appearance and is called acquired radial club hand. There are a few case reports for the treatment of this severe deformity, but there are no proper guidelines for the management of this disease. From our experience, we decided to provide treatment guidelines for acquired radial club hand. Objectives To evaluate the outcome of radial deformity treatment in acquired radial club hand injuries and develop a treatment algorithm. Patients and methods It is a case series study of 11 patients with acquired radial club hand. It was conducted at a tertiary care hospital in Pakistan, from year 2016 to 2022. Basic principles of management of infection and trauma were followed. For the treatment of radial deformity, different options were opted according to the type of deformity, following the principles of treatment of congenital radial club hand. The outcome was graded on functional activity, pain, and bony union. Results Out of 11 patients, 36.36% showed excellent results, 27.27% showed good results, 27.27% showed fair results, and 9.09% showed poor results. Results were excellent in all patients with avascularized bone graft and distraction lengthening, with or without the Darrach procedure. Of the patients in whom distraction lengthening was performed, one patient showed excellent results while the other patient achieved similar results after the Darrach procedure of ulnar shortening. In the case of one bone formation by radioulnar synostosis, the results were variable. Two of the patients showed good outcomes while the other two had fair outcomes. Results in the case of ulnar centralization were mixed with good, fair, and poor results in one patient each. After three months of follow-up, 87% of the patients showed fair to excellent results. Conclusion With our experience, we recommend an algorithm for the treatment of acquired radial club hand.

BACKGROUND: We developed a 2-stage, MTP (metatarsophalangeal) joint- plus ADM (abductor digiti minimi) tendon-transfer, procedure for treatment of hypoplastic thumb. This method is intended to achieve both structural and functional goals of reconstruction. Structurally, it preserves a five-digit hand with minimal donor site complications. Functionally, it provides a functioning opposable thumb.
METHODS: The case series included 7 patients with type IV hypoplastic thumb. At the first stage non-vascularized joint (not bone) was transplanted. In the second stage abductor digiti minimi tendon was transferred. Patients were followed for a median 5-yr period (range: 37-79 months). Functional outcome was assessed using a modified Percival assessment tool. Participants aged 17 to 36 months at the time of surgery with (2 male, 4 female). All patients were able to grasp large and small objects after the procedure. The thumb tip could actively move to touch the tips of index (2 patients) middle, ring, and little fingers (all patients) in an ulnar ward sequence and vice versa. All patients attained the ability to do lateral, palmar, and tripod pinch. As for donor site complications, none of the patients were found to have difficulty walking or keeping their balance.
CONCLUSIONS: An alternative surgical procedure was developed to reconstruct a hypoplastic thumb. We obtained a good functional and cosmetic outcome with few donor site complications. Future studies will be needed to determine the long-term outcomes, to refine the selection criteria and to examine the necessity of additional procedure at the older ages.

Congenital radial longitudinal dysplasia remains an \'unsolved problem\' in hand surgery. The challenges presented by the skeletal deficiency of the distal radius and soft tissue dysplasia of the severe radial longitudinal deficiency have been addressed by a number of techniques that aim to stabilize the position of the hand relative to the forearm and optimize forearm growth and hand function. Analysis of hand function and position in these children is difficult because of the abnormal \'wrist\' mechanics, and the published results of the techniques used to date often lack a standardized approach and importantly the perception of function from the patient\'s perspective. The existing data is reviewed and compared with the results of cohorts from two major congenital upper limb centres. Soft tissue distraction prior to radialization or centralization may offer benefit in ulnar growth and forearm length but there is a need for further research into the long-term functional outcomes of the various techniques available to determine the optimal choice for these children.Level of evidence: V.

One concern in the surgical treatment of radial longitudinal deficiency (RLD) is certainly the skin incision. Over the years many different types have been proposed and used. We propose a new skin incision technique: a double Y sliding flap with the main body along the dorsal wrist crease, followed by raising a proximal and a distal flap providing wide access to the dorsal surface of the wrist joint. After correction of the wrist deformity, skin triangles are resected on the radial and ulnar sides of the incision. Then the skin of the distal flap is slid radially and proximally, filling the defect left by the resected radial triangle, while the proximal flap is slid in the opposite direction, enabling transverse closure along the ulnar side of the incision. The final scar comprises a central body along the dorsal wrist crease, and a radial branch. The aim of this study was to analyze the clinical results of this new double Y sliding flap approach for the surgical treatment of type III and IV RLD. We retrospectively reviewed medical records of surgical correction of RLD using our new incision, between January 2016 and December 2018 in our department of hand surgery. Endpoints comprised correction of redundant skin, scar appearance, and complications. Twelve limbs in 9 patients treated with this double Y sliding flap approach were reviewed: correction of redundant skin was systematic, only 2 limbs showed postoperative complications (1 case of notable edema and 1 of delayed wound healing), and scar aspect was graded good in 11 of the 12 cases. The double Y sliding flap was safe, with minimal complications, adequate skin restoration, wide exposure of the wrist, and esthetically good scar. LEVEL OF EVIDENCE: IV.

OBJECTIVE: Publications evaluating the results of the ulna lengthening in congenital radial deficiency are based only on small groups of subjects which yield statistical studies of low scientific value. The aim was to examine the effectiveness of ulna lengthening in radial longitudinal deficiency and determine the number and quality of complications based on one of the most numerous study groups described in the literature.
METHODS: The material consists of a study group with 31 upper limbs of unmatured patients diagnosed with type III and IV radial longitudinal deficiency. The study group was evaluated based on the parameters known from the literature. The difficulties during elongation were classified according to Paley\'s classification.
RESULTS: The study group contained patients with a mean age of 9 years, and the number of boys and girls was comparable. Ulna length significantly increased after elongation compared to the initial bone length. The patient\'s age didn\'t affect the ulna lengthening, and the amount of elongation didn\'t significantly affect the total stabilization period. However, the total stabilization time increased with increasing patient age. Difficulties affected more than half of the cases.
CONCLUSIONS: Ulna elongation in congenital radial deficiency results in significant lengthening of the ulna, and thus the entire forearm, compared to the initial bone length. This technique has a high percentage of difficulty, so its use should be considered after cautious discussion with the parents and patients.

To study the long-term results of radial club hand, regarding ulna growth, radial angulation, and volar subluxation using a 2-stage treatment protocol.
From 1998 to 2009, 39 radial club hands (32 patients) were treated with distraction, radialization, and a bilobed flap. Long-term follow-up was available in 13 patients (17 hands; average 12.6 years, range 9-16 years). All 17 hands were classified as Bayne and Klug grade 3 or 4.
The average age at distraction was 12 months (SD 5.3). The average age at radialization was 14 months (SD 5.8). At final follow-up, the average ulna length on the involved side was 69.3% of the uninvolved contralateral side in the unilateral cases. In the 4 bilateral cases, the average ulna length was 62% of the ulna length of a cohort of normal children. The transverse diameter of the ulna in the posteroanterior view was 79%, and in the lateral view 99%, of the radius on the contralateral side in the unilateral cases. The average radial deviation improved from 82° to 8° and the average volar subluxation improved from 20° to 12°. However, in 4 hands recurrent volar subluxation and required revision surgery.
This approach to treatment was associated with consistent results in the correction of the radial angulation, volar subluxation, and ulna growth in long-term follow-up. Volar subluxation may result in a requirement for revision.
Therapeutic IV.

To report the histopathological, electron microscopic, and immunohistochemical findings of tissue samples obtained from patients with radial longitudinal deficiency (RLD) and investigate the contribution of abnormality in soft tissues as a secondary driver of deformity in RLD.
Specimens from radial-sided muscles and tendons were obtained at the time of surgery (either radialization or centralization) from 14 patients with 16 limbs affected with Bayne type 3 and type 4 RLD. The specimens were evaluated using light microscopy, electron microscopy, and immunohistochemical examination.
Among the 16 frozen muscle specimens, 6 (37%) showed normal muscle, while 10 (63%) showed the presence of atrophic fibers. The 6 cases with normal muscle showed no abnormality in fiber type distribution. Six patients showed predominance of type 1 muscle fibers. None of the specimens had myofibroblasts; 4 of 16 specimens had mast cells, and 9 of 16 specimens showed the presence of platelet derived growth factor-positive cells. Features of myofibroblasts (the presence of basal lamina, intercellular junctions, or pinocytic vesicles) were not identified in any specimen on electron microscopy.
The histopathological, electron microscopic, and immunohistochemical findings, in particular the absence of myofibroblasts, in tissue samples obtained from patients with RLD, do not support the assumption of abnormality in soft tissues as a secondary driver of deformity in RLD.
This study provides a preliminary insight into a possible role of soft tissues in the development of the deformity in RLD.

(1) Background: Patients treated with the two previous generations of ulnarization developed a bump related to the ulnar head becoming prominent on the radial side of the hand. To finally remedy this problem, a third generation of ulnarization was developed to keep the ulnar head contained. While still ulnar to the wrist center, the center of the wrist remains ulnar to the ulnar head, with the ulnar head articulating directly with the trapezoid and when present the trapezium. (2) Methods: Between 2019 and 2021, 22 radial club hands in 17 patients were surgically corrected with this modified version of ulnarization. (3) Results: In all 17 patients, the mean HFA (hand-forearm-angle) correction was 68.5° (range 12.2°-88.7°). The mean ulna growth was 1.3 cm per year (range 0.2-2 cm). There were no recurrent radial deviation deformities more than 15° of the HFA. (4) Conclusions: This new version of ulnarization may solve the problem of the ulna growing past the carpus creating a prominent ulnar bump. The results presented are preliminary but promising. Longer-term follow-up is needed to fully evaluate this procedure.

Radial longitudinal deficiency is a rare skeletal anomaly characterized by a defect in the development of structures that form the radial half of the forearm. The disorder is associated with a large spectrum of preaxial abnormalities. It is shown that the thumb and preaxial carpal bones are almost always hypoplastic or absent in almost all types of radial longitudinal deficiency. Congenital dislocation of the dysplastic radial head may accompany this rare deformity. Herein, we present a 20-year-old male patient with radial longitudinal deficiency who had a markedly hypoplastic radius but had a thumb and carpal bones with normal size, shape, and joint relations. Further, the right radial longitudinal deficiency of our patient was unusually accompanied by left congenital radial head dislocation. Our case shows that, although rare, radial longitudinal deficiency can present without any carpal and thumb abnormalities. And the current case also shows that a contralateral sided congenital radial head dislocation may accompany radial longitudinal deficiency.

Radial club hand deformities are commonly treated with arthrolysis to allow centralization of the ulna. In this retrospective cohort study of 31 hands in 28 patients, we aimed to assess the outcomes of correction using progressive distraction and subsequent percutaneous pinning of the wrist with a corrective ulnar osteotomy. Mean follow-up time was 7 years (range 2 to 20). The angulation of the hand-forearm complex was decreased after each step of the procedure. Mean correction of the angulation was 64°, and the residual total forearm-hand angulation was 12° after completion of the surgery. At the time of bony maturity (four patients), all wrists had fused. Fifty-eight reoperations were required in 31 wrists because of pin migration or breakage, and in addition 18 secondary osteotomies of the ulna were performed. From this study we conclude that distraction and pinning provide satisfactory and stable realignment of the wrist to correct the deformity, but this treatment has drawbacks regarding the high number of reoperations and the loss of wrist mobility.Level of evidence: IV.