Three-dimensional MRI analysis of elbow anatomy and kinematics in children with ulnar dimelia.

Ulnar dimelia often presents with restricted elbow movement. To develop a treatment strategy to improve elbow mobility, a detailed understanding of the skeletal deformity is needed. We created 3-D models of the cartilage and bone in the elbows of four children with ulnar dimelia by segmentation of MRI scans. We analysed the anatomy and performed a kinematic analysis. In all four children, the distal humerus was triangular in shape and consisted of a medial epicondyle, an enlarged lateral epicondyle and an anterior epicondyle. By comparing the 3-D images with conventional radiographs, we found that the projection of the enlarged lateral epicondyle created two longitudinal lines, which is a radiographic hallmark feature of the triangular-shaped distal humerus. In addition, during elbow flexion, the radial forearm bone slides along the lateral trochlea rather than rotates. This knowledge can aid surgeons to plan treatment for improving elbow mobility in ulnar dimelia.Level of evidence: IV.

Heterotopic respiratory mucosa as a potential source of ectopic Sonic hedgehog (SHH) in the development of complex radial polydactyly and ulnar dimelia.

We report eight cases of complex radial polydactyly and/or ulnar dimelia each with a fistulous lesion of heterotopic respiratory mucosa in radial-anterior skin ranging from shoulder to wrist. Although speculative, the coincidence of these rare conditions suggests a mechanistic relationship.

The unsolved problem of radial longitudinal dysplasia: how can we reliably prevent recurrence, preserve growth and optimize function?

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.

Distal Dorsal Dimelia: A Disturbance of Dorsal-Ventral Digit Development.

PURPOSE: Congenital palmar nail (distal dorsal dimelia [dDD]) of the hand is a rare malformation most commonly affecting the little finger. The purpose of this report was to review the features and associations of this rare disorder and discuss the suspected underlying etiology in light of our current understanding of developmental biology. METHODS: In this retrospective cohort study from 3 practices, we describe our collective experience and review the reported literature on this disorder both as an isolated condition and in conjunction with other anomalies. RESULTS: We examined 15 fingers with dDD, 5 of which involved little fingers. We also found dDD in 6 cases with radial polydactyly (preaxial polydactyl type II [PPD2]) and in 1 case of cleft hand involving digits adjacent to the clefted web space (the index and middle fingers). Cases of little finger dDD were also associated with prominent clefting of the adjacent web space in 4 of 5 cases. All cases had stiffness of the interphalangeal joints and loss of palmar creases consistent with dorsalization of the palmar aspect of the digit. When combined with 63 fingers reported in the literature with dDD, 3 patterns were evident. The most common form occurred in little fingers (n = 50; 64%; dDDu). The next most common form was reported in association with cleft hands (n = 16; 21%; dDDc). Radial digits in association with either radial polydactyly (PPD2) or radial longitudinal deficiency were also susceptible to dDD (n = 12; 15%; dDDr). CONCLUSIONS: Congenital dDD is a disturbance of terminal dorsal-ventral digit patterning. The distribution of this condition with little fingers, clefting, and altered radial digit formation (PPD2 or radial longitudinal deficiency), as well as recent genetic and animal studies, suggests that dDD and altered dorsal-ventral patterning are linked to abnormal apical ectodermal ridge boundary formation. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

A Matched Comparative Study of the Bilhaut Procedure Versus Resection and Reconstruction for Treatment of Radial Polydactyly Types II and IV.

PURPOSE: To compare outcomes of the Bilhaut procedure with outcomes of conventional resection and reconstruction in radial polydactyly types II and IV. METHODS: Patients treated with the Bilhaut procedure were radiologically matched with patients treated with reconstruction. Evaluated outcomes included the Rotterdam assessment system, pinch strength, and thumb size measurements. To determine objectively which aesthetic outcome scores truly depended on surgical technique rather than observer opinion, we analyzed evaluations by a panel of 22 individuals with varying clinical experience who were blinded to the study protocol, using a linear mixed regression model. RESULTS: The Bilhaut procedure reduced the risk of suboptimal outcome for metacarpophalangeal joint instability in type IV radial polydactyly. Conversely, the Bilhaut procedure increased the risk of suboptimal scar appearance, residual prominence at amputation site, thumb size, and nail appearance. Tip pinch strength was more significantly reduced after the Bilhaut compared with reconstruction, whereas pulp circumference and nail width exceeded 100% of the unaffected contralateral hand after the Bilhaut reconstruction. There was no significant difference in active range of motion between procedures. Nail appearance proved the only aesthetic drawback of the Bilhaut procedure after adjustment for clinical experience. CONCLUSIONS: There was superior metacarpophalangeal joint stability after the Bilhaut procedure for radial polydactyly type IV, but this did not result in the presumed benefit to thumb strength. For experienced surgeons, both procedures resulted in comparable thumb active range of motion. However, aesthetic results were more likely perceived as pleasing after conventional reconstruction, even after adjusting for observer experience with regard to nail appearance. Despite possible benefits of modified Bilhaut procedures that preserve the nail, conventional reconstruction is the preferred procedure until otherwise proven. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Analysis of Sequelae after Pediatric Phalangeal Fractures.

INTRODUCTION: The majority of pediatric phalangeal fractures yield excellent results following conservative or operative treatment. However, a certain subset of fractures is associated with long-term sequelae such as osteonecrosis, physeal growth arrest, malunion, and malposition. PATIENTS AND METHODS: This study summarizes all sequelae following phalangeal fractures treated within a 10-year period (2003-2012). The underlying fractures were analyzed and classified in fractures with extensive soft tissue involvement, fractures involving the joint and adjacent bony parts, neck fractures, fractures complicated by infection and sequelae after simple fractures following inadequate initial treatment. RESULTS: In total, 40 patients (27 males; 13 females) with a mean age of 6.2 years (range, 1-18 years) were treated for sequelae following fractures of the phalanges. Ten patients (6 males; 4 females) developed sequelae (limited range of motion, premature physeal closure) following fractures with extensive soft tissue damage. Thirteen patients presented with sequelae (mostly limited range of motion, premature physeal closure) following fractures involving the joint and adjacent bony parts of the phalanges. Transcondylar and subcondylar neck fractures leading to sequelae were seen in 10 patients. Sequelae consisted of limited range of motion in nine and malposition in six cases. In half of the patients, osteonecrosis (n = 5) and premature physeal closure (n = 5) complicated the clinical course. Three patients with open fractures and four patients with inadequate initial treatment presented with sequelae. CONCLUSION: Most sequelae of phalangeal fractures are consequences of fracture per se and are therefore fateful. However, the degree and severity of the long-term sequelae can be minimized by a correct and timely treatment.