The anatomy and treatment of camptodactyly of the small finger

Camptodactyly: From Embryological Basis to Surgical Treatment

Camptodactyly is a relatively rare hand deformity presenting as the proximal interphalangeal joint's nontraumatic and progressive flexion contracture. Most cases are limited to the fifth finger. The severity and type of camptodactyly should be considered to optimize treatment. Since many structures at the finger base can be involved in the pathogenesis of the deformity, surgical treatment for this particular type of deformity is challenging. This paper aims to bring insight into camptodactyly's pathogenesis and treatment options. We discuss the indication and pitfalls of surgical treatment options for particular camptodactyly types and present a case of a fourteen-year-old boy who was admitted to our department with proximal interphalangeal joint flexion contracture of the left fifth digit.

Surgical Treatment of Camptodactyly with Malek Cutaneous Approach and Stepwise Release: A Retrospective Multi-centre Study

Background: Clinical manifestations of camptodactyly are varied and no official consensus on the etiopathogenesis or best treatment is available. Conservative treatment is generally preferred and, in refractory patients, surgery might be considered. However, reported results of surgery are often unsatisfactory and it is difficult to compare outcomes as different classification systems are adopted. We reported the outcomes of surgical treatment of camptodactyly with the Malek cutaneous approach and stepwise release, assessed using the Siegert classification. Methods: A retrospective analysis of paediatric patients (≥1 and ≤18 years) with congenital camptodactyly refractory to conservative management (flexion contracture >30°), treated with Malek cutaneous approach and stepwise release surgery between June 2009 and June 2019 with at least 1 year of follow-up was performed. Pre- and post-operative clinical and radiographic assessments were evaluated for degrees of flexion contractures and early (<30 days) or late (>30 days) complications were recorded. Results: A total of 59 patients underwent surgery, of whom 38 (64%), including 42 fingers, were enrolled; mean patient age was 8 years (range 1-18). Post-operative mean flexion contracture was significantly improved (p > 0.001) and no infections were recorded. Mean follow-up was 6 years (range 1-10) and proximal interphalangeal joint extension deficits were rated according to Siegert classification as excellent (69%), good (12%), or fair (9.5%) and poor (9.5%). Conclusions: The Malek cutaneous approach and stepwise release of the retracting soft tissues allow prompt evaluation of the anatomical structures involved in the deformity and seem to be an effective surgical correction in the long term. Level of Evidence: Level IV (Therapeutic).

One-Stage Extension Shortening Osteotomy for Syndromic Camptodactyly

Syndromic camptodactyly often affects multiple fingers, and severe deformities are common compared to idiopathic camptodactyly. This study aimed to evaluate the use of a one-stage extension shortening osteotomy of the proximal phalanx for patients with syndromic camptodactyly without tendon surgery. Forty-nine cases of syndromic camptodactyly were included. Forty fingers (81.6%) were associated with arthrogryposis multiplex congenita, and nine (18.4%) with other syndromes. Six fingers presented with a moderate form (30° to 60°) of camptodactyly, whereas 43 fingers manifested the severe form (>60°). The mean age at the time of surgery was 8.5 years, and the patients were followed for a mean of 3.9 years. The mean length of the shortening of the proximal phalanx was 4.9 mm, which averaged 17.8% of the proximal phalanx’s original preoperative length. The mean operative time was 25.8 min, and the PIP joint was fixed using Kirschner wires with an average flexion position of 7.6°. The mean flexion contracture improved from 76° preoperatively to 41° postoperatively. The mean preoperative active arc of motion was 23°, which improved to 49° postoperatively. A one-stage extension shortening osteotomy is a straightforward and effective technique for the improvement of finger function through the indirect lengthening of volar structures without the flexor tendon lengthening. The osteotomy could simultaneously correct bony abnormalities. This simple procedure is especially suitable for surgery on multiple fingers in patients with syndromic camptodactyly.

Surgery and Conservative Management of Camptodactyly in Pediatric Patients: A Systematic Review

Camptodactyly is a pediatric hand condition, the treatment of which remains controversial. The authors' aim was to improve patient care through clarifying the definition of camptodactyly and indications for surgical and/or conservative management, summarizing outcomes, and defining risks. A systematic review was conducted of articles in all languages on outcomes following surgical and/or conservative management of idiopathic camptodactyly in children using MEDLINE (Medical Literature Analysis and Retrieval System Online), PubMed, EMBASE (Excerpta Medica database), AMED (Allied and Complementary Medicine), and CINAHL (Cumulative Index of Nursing and Allied Health Literature) (until January 2017). The primary outcome was posttreatment flexion contracture, and the secondary outcomes were indications for surgery, complications, and patient satisfaction. Database searching generated 16 final articles, with 7 case series and 9 retrospective cohort studies. There was a lack of consistency on the definition of camptodactyly and in outcome reporting. All 16 studies received a "Weak" global rating and demonstrated low-quality evidence, suggesting that treatment of camptodactyly with operative or nonoperative measures reduces the degree of flexion contracture in most patients (from pretreatment averages of 20°-85° to posttreatment averages of 5°-37°). There was general agreement that surgery should be reserved for contracture >30° or failure to respond to conservative management. Surgery generally led to more complications compared with conservative management. Only one study reported on functional limitations, and another reported on patient-reported outcomes. Current evidence of the effectiveness of camptodactyly treatment in addressing both joint-specific deformity and patient-perceived function and appearance is insufficient to guide patient care. Future research may consider the development of decision aids to guide patients and families through selecting management strategies and to promote shared decision making.

Camptodactyly resulting from anatomical variation of lumbrical muscles: imaging findings

We report three cases of camptodactyly in adolescent patients, presenting with a passive flexion deformity of the fifth finger. Ultrasound findings include aberrant lumbrical insertion and decreased lumbrical size, confirmed with magnetic resonance imaging, and aberrant dynamics. Surgery confirmed these findings in one patient. To the best of our knowledge, these imaging findings have not been reported previously.

Camptodactyly Caused by an Anomalous Origin of the Flexor Digitorum Superficialis Tendon: A Case Report and Review of the Literature

Camptodactyly is a flexion contracture of the proximal interphalangeal joints and is known as an isolated malformation that affects 1 in 300 in the population and can be inherited as an autosomal dominant trait with variable expression.

A 17-year-old female was referred to the Clinic of Plastic Surgery, University Clinical Center of Kosovo, Prishtina, for the first time with camptodactyly of the little finger in the right hand. She was presented with a progressive flexion contracture of the proximal interphalangeal joint greater than 110 degrees of her right little finger.

According to our observations from outpatient consultations, we concluded that the case of camptodactyly in the little finger in the flexible form (>110 degrees), which underwent surgical treatment, presented excellent result. Therefore, we think that the surgical technique used in our case report will contribute to treating this complicated deformity.

Camptodactyly: An unsolved area of plastic surgery

Background

Camptodactyly refers to permanent flexion contracture at the proximal interphalangeal joint. Most cases are limited to fifth-finger involvement. Although common, the treatment of camptodactyly is controversial. Many published studies have emphasized conservative treatment, while others have described surgical procedures. The problem with this deformity is that it presents in several forms, which means that there is no single model for effective treatment. The aim of this paper is to present the difficulties encountered with this condition and the management thereof on an individual basis.

Methods

This is a case series of 14 patients (nine males, five females) who underwent surgical treatment. The results were classified using the method from Mayo Clinic as excellent, good, fair, and poor.

Results

Fourteen patients with 15 fingers underwent surgery, and the results achieved were as follows: excellent, 0; good, 1; fair, 6; poor, 8. The treatment of camptodactyly still remains controversial, and hence proper planning individualized to each patient is needed to achieve the maximal improvement with realistic goals.

Conclusions

Although we performed individualised surgery, our careful follow-up was not able to identify any method as superior over another with respect to gain in extension and loss of flexion. We therefore propose that the extensor mechanism should not be disturbed during surgery to treat camptodactyly cases.

Treating Congenital Proximal Interphalangeal Joint Contracture

The management of congenital proximal interphalangeal joint deformity, also known as camptodactyly, is challenging. There are numerous theories on the cause of this abnormal finger posture, leading to variations in classification, definition, and treatment approaches. This article assesses the previous literature and provides clarity and guidance for the practical treatment of camptodactyly.

Early Results of Surgical Management of Camptodactyly

BACKGROUND

We hypothesize that surgery for moderate-to-severe camptodactyly (>50 degrees) results in modest gains in range of motion and improved digital position.

METHODS

A retrospective analysis of patients undergoing surgery for camptodactyly at a tertiary children's hospital between 2000 and 2014 was performed. Surgery was indicated for patients with persistent, functionally limiting flexion contractures despite observation, therapy, and splinting. Data were collected on demographics, clinical history and presentation, nonoperative management, surgery, and clinical follow-up, focusing on range of motion at the involved joint. Total passive motion (TPM) and total active motion (TAM) at the proximal interphalangeal (PIP) joint was calculated at presentation, preoperative visit, first postoperative visit out of the cast, and last follow-up visit. Average postoperative follow-up was 1.4 years.

RESULTS

In total, 31 digits in 22 patients were reviewed. There were 13 males; average age at surgery was 9.6 years. There were 7 type I (infantile), 8 type II (adolescent), and 7 type III (syndromic) patients. All cases involved the PIP joint; 55% involved the small finger. All patients underwent sequential release of contracted structures until maximal extension without compromising vascularity or joint stability was obtained. Z-plasty of the volar skin was performed in 68% of digits, flexor digitorum superficialis tenotomy in 77%, volar plate release in 58%, and collateral ligament release in 48%. All patients were casted postoperatively for an average of 31 days, and 71% of digits had temporary transarticular pin fixation. At initial presentation, mean TPM and TAM were 34 and 24 degrees, respectively. TPM and TAM were 32 and 19 degrees immediately preoperatively, 30 and 13 at the first postoperative visit, and 35 and 25 at the final follow-up. Furthermore, the position of PIP arc of motion was in a more extended position postoperatively. Average TPM arc of motion was from 50 to 82 degrees preoperatively and 28 to 63 degrees at final follow-up; average TAM arc of motion was 62 to 81 degrees preoperatively and 30 to 55 degrees at final follow-up. There were no clinically meaningful differences in results based on camptodactyly type, preoperative motion, or age at surgery. There were no cases of wound infection or dehiscence. Two patients with recurrent contractures opted for subsequent PIP arthrodesis.

CONCLUSIONS

Total motion of the PIP joint was similar both preoperatively and postoperatively following surgical release of camptodactyly. However postoperatively, the digit was in a more extended position over this arc of motion. For patients with functionally limiting flexion contractures, surgical release may be beneficial by providing a more extended position, for improved digital release, hygiene, and esthetics.

LEVEL OF EVIDENCE

Level IV.

Severe camptodactyly: A systematic surgeon and therapist collaboration

INTRODUCTION

Although common, the treatment of camptodactyly is controversial.

PURPOSE

Our purpose is to delineate a logical stepwise treatment plan based on corresponding components of the pre-operative and intraoperative evaluation of camptodactyly. In addition, describe structure rehabilitation plan utilizing the same stepwise evaluation.

METHODS

With the use of a retrospective cohort study design, we reviewed 18 consecutively operated digits in twelve patients with camptodactyly affecting the proximal interphalangeal (PIP) joint. There were five girls and eight boys, averaging eight years of age (range: 9 months to 15 years) at surgery.

RESULTS

Surgery corrected flexion contractures with mean post-operative flexion contracture of 3° (range 0-25°) at mean follow-up of 11 months (range 3-32 months). 15 of 18 digits achieved full active PIP extension.

DISCUSSION

By employing a detailed clinical assessment to guide surgical treatment followed by focused therapy, we have markedly improved flexion contractures in digits with moderate to severe camptodactyly.

CONCLUSIONS

Hand therapy is essential to maintain and further surgical improvement of passive extension and to regain active extension following surgery.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Evaluation of treatment for camptodactyly: retrospective analysis on 40 fingers

Objective

to retrospectively assess the results from cases treated in the hand surgery service, starting from a preestablished protocol; and to conduct a critical analysis on the results achieved, with separation of the cases into their respective subgroups.

Methods

twenty-three patients and a total of 40 fingers were evaluated between January 2004 and December 2011. We correlated the altered anatomical structures found in the cases that underwent the surgical procedure and its results, with regard to both conservative and surgical treatment, emphasizing the main indications.

Results

the results were analyzed using the Sierget method of the Mayo Clinic.

Conclusion

we observed that the cases of camptodactyly of the little finger alone in the flexible form (>60°) that underwent surgical treatment uniformly presented excellent results. In the rigid forms, our observations indicated that there were benefits comprising gains of extension and correction of the deformity. However, the range of motion with active flexion in the proximal interphalangeal joint was always partial. With evolution over time, some cases presented some loss of the gain previously achieved, which corroborates the need for continual vigilance during the follow-up, with systematic use of braces until the final phase of skeletal growth.

Multidigit camptodactyly of the hands and feet: A case study

A clinical case of a 12-year-old boy who presented with multidigit, nonsyndromal, progressive camptodactyly is discussed. While bilateral little finger camptodactyly is well described, there is no documentation of camptodactyly involving all fingers and many toes as well as both proximal (PIP) and distal interphalangeal (DIP) joints. This patient responded well to surgery, which was performed on four toes and seven fingers, despite having established radiographic changes of camptodactyly in the PIP joints as well as two DIP joints. This case illustrates that in the skeletally immature patient, successful surgical outcomes can occur even in patients with radiographic bone changes, which themselves may be reversible following PIP contracture release. This patient's separate fingers presented with deformity at different stages. A single patient with multiple digit involvement is illustrative of the range of clinical presentations and treatment options for camptodactyly. This article serves to inform hand surgeons about the potential consequences of avoiding surgical treatment, the need for a severity staging system, and the breadth of presentations in camptodactyly.

Genome-wide association scan of Dupuytren's disease

PURPOSE

Dupuytren's disease (DD) has a strong genetic component that is suggested by population studies and family clustering. Genetic studies have yet to identify the gene(s) involved in DD. The purpose of this study was to identify regions of the entire genome (chromosomes 1-23) associated with the disease by performing a genome-wide association scan on DD patients and controls.

METHODS

We isolated genomic DNA from saliva collected from 40 unrelated DD patients and 40 unaffected controls. We conducted the genotyping using CytoSNP-Infinium HD Ultra genotyping assay on the Illumina platform. Using both log regression and mapping by admixture linkage disequilibrium analysis methods, we analyzed the single nucleotide polymorphism genotyping data.

RESULTS

Single nucleotide polymorphism analysis revealed a significant association in regions for chromosomes 1, 3 through 6, 11, 16, 17, and 23. Mapping by admixture linkage disequilibrium analysis showed ancestry-associated regions in chromosomes 2, 6, 8, 11, 16, and 20, which may harbor DD susceptibility genes. Both analysis methods revealed loci association in chromosomes 6, 11, and 16.

CONCLUSIONS

Our data suggest that chromosomes 6, 11, and 16 may contain the genes for DD and that multiple genes may be involved in DD. Future genetic studies on DD should focus on these areas of the genome.

Effect of passive stretching on simple camptodactyly in children younger than three years of age

PURPOSE

To present the effectiveness of passive stretching as a treatment for camptodactyly, without any other form of physiotherapy or splinting.

METHODS

From May 2003 to August 2008, 61 digits of 22 patients were treated conservatively using passive stretching exercises. All children were less than 3 years old and had no other anomalies. Flexion contractures before and after treatment in mild, moderate, and severe groups were measured and changes were analyzed statistically. The correlations between various clinical factors and treatment outcome were also analyzed statistically. The average follow-up period was 26 months (range, 12-47 mo).

RESULTS

Mean flexion contracture improved from 20° to 1° in the mild group (p < .001), from 39° to 12° in the moderate group (p < .001), and from 75° to 28° in the severe group (p < .001). Of the clinical factors examined, only initial flexion contracture was found to be significantly correlated with treatment outcome (r = -0.287, p = .0025).

CONCLUSIONS

Passive stretching can effectively improve flexion deformity in camptodactyly in infants and young children.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Reconstruction of congenital differences of the hand

SUMMARY

Congenital differences of the upper limb occur in approximately 0.16 to 0.18 percent of live births. These patients provide a unique challenge for the reconstructive hand surgeon. The correct and timely diagnosis of hand and upper limb congenital differences will lead to appropriate care and rehabilitation. The International Federation of Societies for Surgery of the Hand has classified congenital upper limb differences based on abnormalities of embryogenesis: failure of formation of parts, failure of differentiation of parts, duplication, overgrowth, undergrowth, constriction ring syndrome, and general skeletal abnormalities. This classification scheme is used as a basis for discussion of the most common upper limb anomalies. Both surgical and nonsurgical treatments are discussed, as is appropriate timing of intervention.

Failure of differentiation: Part II (arthrogryposis, camptodactyly, clinodactyly, madelung deformity, trigger finger, and trigger thumb)

The term "failure of differentiation" describes the phenotypes of a large number of otherwise unrelated conditions. The six conditions described here (arthrogryposis, camptodactyly, clinodactyly, Madelung deformity, trigger finger, and trigger thumb) are believed to occur because various structures failed to differentiate normally; however, they have neither common features nor a common cause. We have included information about the history and diagnosis of these conditions, the cause (if known), and the current concepts of treatment and expected outcomes.

Surgical correction for curly toe using open tenotomy of flexor digitorum brevis tendon

Curly toe is a common congenital deformity characterized by flexion and varus deformity of the interphalangeal joints. Because this minor deformity is seldom accompanied with any symptoms, treatment strategy has rarely been discussed in detail in the literature. Eight toes in seven patients with curly toe were treated by open tenotomy of the medial slip of the flexor digitorum brevis tendon. If sufficient correction was not obtained, the collateral ligament and the volar plate of the proximal interphalangeal joint were dissected. The skin defect at the plantar base of the toe was covered using a local flap or a full-thickness skin graft. The median age at operation was 2 years 6 months (ranged from 8 months to 5 years 4 months). In all cases, contracture of the plantar skin at the base of the toe and tight FDB tendon were recognized to a variable degree. Postoperatively, overlapping of the affected toe was corrected in every case at a median follow-up of 2 years 9 months. However, flexion and/or varus deformity tended to remain to some degree in those patients with severe curly toe. Toes with moderate to severe deformity with overlapping beneath the adjacent toe are candidates for surgical correction, because spontaneous correction is unlikely and troublesome symptoms may occur as the child grows older. Surgical correction should be performed until 2-3 years of age. The postoperative result might be poor, if treated in the older age, because skeletal deformity is likely to occur. Open tenotomy of the FDB tendon is easy to perform, and toe function was seldom impaired.

Treatment of congenital upper extremity problems

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the terminology and classification of congenital hand anomalies. 2. Describe the incidence and embryogenesis of some common congenital hand anomalies. 3. Discuss the general principles and goals for treatment of congenital hand anomalies. 4. Describe the management of five of the more common congenital hand anomalies (syndactyly, short digits, thumb duplication, hypoplastic thumb, and radial dysplasia).

SUMMARY

Congenital hand anomalies can cause substantial emotional and functional problems. This article reviews the etiology, classification, and management of some of the more common hand anomalies. A general approach to the patient and the goals of treatment are reviewed, as is the approach to five specific congenital hand anomalies: syndactyly, short digits, thumb duplication, hypoplastic thumb, and radial dysplasia.

Distraction - A Minimally Invasive Technique for Treating Camptodactyly and Clinodactyly

Camptodactyly and clinodactyly are relatively common congenital anomalies affecting about 1% to 2% of the general population. Though functional impairment is uncommon other than in very severe cases, patients affected do present very often for correction. The kind of surgeries available is as diverse as the aetiology of the conditions. It ranges from simple release of the flexor digitorum sublimis (FDS) to more complex small muscle transfers, rebalance etc. In this short series a relatively easier, minimally invasive technique of distraction has been used to correct these deformities with gratifying results.

[Camptodactylies]

Camptodactyly is a permanent non-traumatic flexion contracture at the proximal interphalangeal joint, involving most of the time the fifth finger. This condition is rare (incidence is inferior to 1%). Most of the cases are sporadic, although some authors have traced the transmission through several generations. Two types of camptodactyly have been described, depending on the age of onset (within the first year of age or in adolescent). This condition can also be described as "static" or "dynamic", depending on the effect of MP flexion on the PIP extension lag. Many anatomical abnormalities have been evoked as potential aetiology for camptodactyly, including variations in the lumbrical or flexor superficialis origin or distal insertions. However, after a few years without treatment, permanent flexion position of the joint adds its own effects and leads to joint contracture, regardless of the aetiology of camptodactyly. Treatment is required for this condition for extension deficit greater than 30 degrees. The first step will always consists of dynamic splinting of the PIP joint. If improvement is not obtained through dynamic splinting alone, surgery can be considered. Correction of a well defined anatomical abnormality is part of the treatment. When required, it will be associated to correction of joint and soft tissue contracture.

Congenital anomalies: a 25-year overview

Expansion of the discipline of hand surgery and heightened interest in congenital problems have resulted in major advances in the treatment of congenital hand anomalies over the past 25 years. Increased experience with congenital anomalies of the hand has expanded the hand surgeon's knowledge of patterns and relationships between different anomalies resulting in new methods of classification and more logical approaches to treatment. The principles of treatment of the more common anomalies, such as syndactyly, established by prior generations of hand surgeons have been refined in details of technique. New technologies, such as distraction lengthening and free vascularized transfers, have allowed the surgeon to treat new problems and old problems in new ways. In spite of our successes, much remains to challenge hand surgeons in this new millennium, especially in the construction of joints and the expanding field of fetal surgery.

Camptodactyly: a unifying theory and approach to surgical treatment

Camptodactyly is an isolated congenital flexion deformity of the proximal interphalangeal (PIP) joint. Surgical experience with 16 patients (18 fingers) between June 1983 and December 1994 is reported. Skin, fascia (retinaculum cutis), tendon sheaths, flexor digitorum superficialis tendon, lumbricals and interossei (particularly the lateral bands), joint surfaces, neck of the proximal phalanx, and central slip insertion were involved in all cases, although the degree of involvement can vary. Surgery must address all of these structures. Postoperative splinting is important. Fifteen patients had good or excellent results after surgery, with a mean gain in motion of 57 degrees (range, 0 degrees-90 degrees). Surgery should be aimed at prevention of progressive deterioration and is probably not indicated in minor degrees of the deformity. Surgery should be reserved for patients with a preoperative PIP joint contracture of more than 60 degrees.

Camptodactyly caused by an anomalous origin of the flexor digitorum superficialis tendon. Case Report

A 20 year old man with a progressive flexion contracture of the proximal interphalangeal joint of his right ring finger had an anomalous origin of the flexor digitorum superficialis tendon. After excision of the aberrant flexor tendon the patient had a normal range of movement of the proximal interphalangeal joint.

[Surgical treatment of camptodactyly]

Almost all anatomical structures of the hand have been held responsible for non-traumatic, non-paralytic flexion deformity of the proximal interphalangeal joint. Together with Millesi and Flatt, we define camptodactyly as a disorder of flexor-extensor equilibrium in the PIP. This definition determined our therapeutic approach. 59 patients with one or several fingers affected by camptodactyly were followed between 1975 and 1989. In 3 cases, the anomaly was associated with another malformation of the hand and 56 cases, it was isolated. 11 children did not receive any active treatment, but were followed and manipulated. 17 (27 fingers) were treated by static or dynamic splints. 31 (43 fingers) were operated according to the following technique: total anterior tenoarthrolysis leading to recession of the flexor apparatus and lengthening of the skin on the palmar surface of the first phalanx by a rotation flap. This operation was preceded and followed by application of a dynamic extension splint onto the operated finger. Of the 20 fingers treated by manipulations and reviewed, 11 had improved, 7 were stable and 2 had deteriorated. Of the 24 fingers treated by splints and reviewed, 14 had improved, 5 were stable and 5 had deteriorated. Of the 30 fingers operated and reviewed, 30 had improved, 7 were stable and 2 had deteriorated. Although recent anatomical studies tend to indicate that anomalies of the lumbrical muscles are frequent in operated camptodactyly, these studies do not take into account the numerous anomalies of these muscles observed in the general population. The therapeutic conclusion resulting from these studies are also unconvincing. The technique which we propose cannot be applied to every case. The milder forms only require orthopaedic treatment. C camptodactyly in adolescents or adults with joint blocking are only slightly improved by surgery and only require corrective osteotomy. In all other cases, especially in young children, anterior tenoarthrolysis of the finger with cutaneous elongation allows reduction or correction of the deformity.

Camptodactyly resulting from paradoxical action of an anomalous lumbrical muscle

A 17 year old girl presented with camptodactyly resulting from an anomalous insertion of the lumbrical muscle into the flexor digitorum superficialis tendon. The fourth anomalous lumbrical muscle paradoxically caused flexion of the proximal interphalangeal (PIP) joint of the little finger when the patient extended the fingers fully. She was operated on, and the lumbrical tendon was cut at its insertion into the flexor digitorum superficialis tendon. The tight fascial band and skin contracture at the PIP joint were released, and the skin defect covered with a transposed flap. She made a good recovery and eight months after operation had only 40 degrees residual flexion deformity with full flexion of the PIP joint of the little finger.

Camptodactyly caused by abnormal insertion and origin of lumbrical muscle

A 12-year-old boy had camptodactyly of the little finger. Operative findings revealed an abnormal origin of the lumbrical muscle from the transverse carpal ligament, and abnormal insertion into the tendon sheath of the flexor digitorum superficialis tendon. No similar case has been reported in the literature.