|Year : 2014 | Volume
| Issue : 2 | Page : 120-122
Absent flexor digitorum profundus (FDP): An unreported component of camptodactyly
R Santosh1, Nabakishore Haobijam2, Arun Kumar Barad1, Sanjib Singh Nepram2
1 Department of General Surgery, Regional Institute of Medical Sciences, Imphal, Manipur, India
2 Department of Plastic and Reconstructive Surgery, Regional Institute of Medical Sciences, Imphal, Manipur, India
|Date of Web Publication||18-Sep-2014|
Dr. Nabakishore Haobijam
Department of Plastic and Reconstructive Surgery, Regional Institute of Medical Sciences, Imphal - 795 004, Manipur
Source of Support: None, Conflict of Interest: None
Camptodactyly is a rare congenital hand anomaly. It can be a marker for other associated anomalies. It is due to an imbalance between the flexor and extensor forces acting upon the proximal interphalangeal joint. Abnormal lumbrical insertion is the most common contributory factor. FDP absence as a component of camptodacryly is never reported before. Further observations will be needed to know the significance of this finding in planning surgery and the probable outcomes. A brief review of the disease is presented herein.
Keywords: Camptodactyly, Flexor digitorum profundus, Lumbrical
|How to cite this article:|
Santosh R, Haobijam N, Barad AK, Nepram SS. Absent flexor digitorum profundus (FDP): An unreported component of camptodactyly. J Med Soc 2014;28:120-2
|How to cite this URL:|
Santosh R, Haobijam N, Barad AK, Nepram SS. Absent flexor digitorum profundus (FDP): An unreported component of camptodactyly. J Med Soc [serial online] 2014 [cited 2021 May 11];28:120-2. Available from: https://www.jmedsoc.org/text.asp?2014/28/2/120/141103
| Introduction|| |
'Camptodactyly' (Greek for bent finger) is a relatively rare condition which constitutes 5% of congenital hand anamolies.  Most of the cases are sporadic, and have bilateral involvement.  It is most commonly seen in little finger with contractures ranging from 20 to 100 degrees. Although functional impairment is minimal, its appearance prompts visit to a surgeon. Camptodactyly may occur separately or together with other signs characterizing a large number of syndromes. It is considered as a 'marker sign' that should invite physician's attention to the possibility of occurrence of associated malformations.
Camptodactyly is known to have a confusing etiology. Abnormal intrinsic hand muscle anatomy leading to flexion contractures is proposed as the prime etiologic factor. Millesi et al.  opined that camptodactyly is due to an imbalance between the flexor and extensor forces acting upon the proximal interphalangeal joint. Studies in this field are lacking and most of them are limited to isolated case reports and case series, making it difficult to find the true proportions of the intrinsic hand muscle abnormalities. Till date, abnormalities of flexor digitorum superficialis (FDS) and lumbricals are unknown. The abnormality in flexor digitorum profundus (FDP) is unheard of and could be a very rare anatomical defect that needs attention as it will influence the surgical planning as well. Herein, we report a case of camptodactyly in a 29-year-old male with absent FDP- a rare component of camptodactyly.
| Case Report|| |
A 29-year-old male presented with flexion deformity of little fingers of both the hands noticed since 15-20 years. There was no functional impairment. Rejection at the military recruitment prompted him to visit our hospital. There was no past history of trauma or burns to the finger. Initial local examination revealed flexion deformity of bilateral little fingers at the proximal inter-phalangeal joints (PIP). Flexion deformity of around 70° was noted in both the little fingers. Rest of the fingers were normal. The X-rays (anterio-posterior, oblique view) of both the hands revealed narrowing of joint space at PIP joints of both the fingers. Broad base of the middle phalanxes of the little fingers were also noted. The diagnosis of camptodactyly was made. Workup did not reveal any hematological, cardiopulmonary or urinary system abnormalities.
Under regional anesthesia, patient underwent surgery with Bunnel incision revealing the absence of FDP tendon to the little fingers of both the hands and abnormal lumbrical insertion to the little finger. Contracture skin release was done and split skin grafting was done. A 90% flexion contracture correction was achieved.
His post-operative and rehabilitation was uneventful. However, his long-term results are to be followed up.
| Discussion|| |
Camptodactyly is defined as a congenital or acquired non-traumatic flexion deformity of the PIP joint of one or several fingers.  Congenital group constitutes 84% with equal presentation among boys and girls. Non-congenital group manifests after 10 years of age and primarily in females. It may present as an isolated entity or as a part of a spectrum of congenital anomalies.  In 1984, Rozin et al.  elaborated a classification of syndromes with camptodactyly. He observed the occurrence of this sign in 44 different syndromes. Pagnan et al.  in their study found 75 syndromes associated with this deformity. Most common among these syndromes were Freeman-Sheldon syndrome, Larsen syndrome, distal arthrogryposis syndrome type I, Beals syndrome and Aarskog-scott syndrome, etc. However, in our case no other associated anomaly was evident and consequently syndromic association was ruled out.
Camptodactyly must be differentiated from other flexion deformities of the fingers such as boutonnière deformity, Dupuytren's contracture, a trigger finger, congenital absence of the extensor mechanism. 
Camptodactyly has always been an elusive condition with respect to its confusing etiology and management. Engber and Flatt  were of the opinion that there is probably no single cause for the deformity. Millesi et al.  in 1974, postulated that it is due to an imbalance between the flexor and extensor forces acting upon the proximal interphalangeal joint. McFarlane et al.  studied 74 consecutive cases of camptodactyly. They observed lumbrical abnormality in all the cases with abnormal FDS in 47% of the cases, concluding that the loss of normal lumbrical action is the principal cause of this deformity.
Smith and Kaplan  have pointed out that virtually every structure about the base of the finger has been implicated as the major deforming factor. All the reviewed case series points to lumbrical abnormality as the most common factor, followed by the superficialis abnormalities except Siegert et al. , [Table 1]. Other reported abnormalities include absent or hypoplastic FDS with abnormal insertions  [Figure 1], tight superficialis muscle-tendon unit, and intrauterine tenosynovitis. 
|Table 1: Anatomical defects contributing to camptodactyly in different series|
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Currently,  the most culpable factor is thought to be an abnormal lumbrical insertion either into the superficialis tendon just distal to the metacarpo-phalangeal (MCP) joint or into the fibrous flexor sheath or capsule of MCP joint [Figure 2] and [Figure 3]. However, absent FDP tendon as a contributory factor of Camptodactyly was never reported. In our case it was found that the FDP tendon to the little finger was absent along with abnormal insertion of the lumbrical muscle into the MCP joint of the little finger [Figure 4] and [Figure 5]. Our finding adds abnormal/absent FDP to the spectrum of abnormalities contributing to camptodactyly that needs to be considered when planning the surgery.
|Figure 2: Abnormal lumbrical insertion: (a) Bipennate origin with insertion into ring finger. (b) Insertion into flexor sheath. (c) Insertion into flexor tendon. (d) insertion into collateral ligamant of MP joint|
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|Figure 3: Abnormal flexor digitorum superficialis anatomy (a) Origin from profundus tendon of ring finger. (b) Origin from radial base of fifth metacarpal. (c) origin from transverse carpal ligament. (d) Origin from distal forearm|
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The kind of surgeries available is as diverse as the etiology of the conditions. Commonly preferred surgical plan includes simple release of the tight structures (FDS, skin and fascia) combined with the lengthening procedure of the tendon, capsule, skin as necessary. However, conservative treatment by splinting for mild and moderate deformities appears to be better than surgery. Siegert et al.  concluded that operative treatment should be limited to progressive deformities in patients with moderate-to-severe involvement (those with extension loss of 60° or more) and only after conservative treatment has failed. Importance of early post-operative mobilization, together with static and dynamic splinting cannot be undermined. In our case, simple release of the tight structures was undertaken with post-operative splinting. Though short-term results are appealing, long-term follow-up is required.
| Conclusion|| |
Camptodactyly though appears simple, is a complex condition with complex etiologies. Abnormal lumbrical insertion is the most common contributory finding. Surgery should be considered and planned accordingly after an attempted conservative splinting in moderate to severe cases. Simple release of tight structure is the most simple and rewarding procedure. Absent/abnormal FDP can be a component of camptodactyly. It should be considered at planning of surgery in addition to other known contributory abnormalities around the base of the finger. Further observations will be needed to determine the functional outcomes of surgery in the presence of this finding.
| References|| |
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]