Dupuytren’s Contracture With Heterotopic Ossification

Introduction

Heterotopic ossification (HO) is the formation of ectopic lamellar bone in soft tissues. ¹ Although the exact cause is unknown, it is recognized to be a pathological result of orthopaedic trauma, burns, and neurological injuries. ² Heterotopic ossification is often asymptomatic; however, contractures, loss of joint function, and chronic pain can arise as the ectopic bone invades soft tissues. ³ There have been several reports of the development of HO after major orthopaedic procedures, such as joint replacements. ⁴ Although osteophyte formation is known to be associated with Dupuytren disease, ⁵ HO of the hand is less understood. We present a case where HO developed within a Dupuytren contracture. To the best of our knowledge, this is the second case reported ⁶ and the only to have captured preoperative radiographs of the pathology.

Case Presentation

A 61-year-old right-handed male presented with recurrent left fifth finger Dupuytren’s contracture of the proximal interphalangeal joint (PIPJ) and a left hand thenar mass. The patient had a history of palmar digital fasciectomies for Dupuytren disease in other digits and had 2 previous operations on this left fifth finger, the most recent being 3 years prior. He also had previous open fasciectomies for left hand Dupuytren disease of the third, fourth, and fifth digits 8 years earlier. The thenar mass was present for approximately 1 year, in which time it became progressively larger but did not cause any compression symptoms or functional issues. His past medical history was significant only for gout and osteoarthritis of the knees and he was not taking any medications. He worked in security and was a non-smoker. Multiple family members also had a history of Dupuytren disease.

Examination of the hand revealed a 90° of contracture of the PIPJ of the left fifth digit and evident scar tissue of the palmar fascia from his previous open fasciectomies. The mass of the thenar eminence was non-pulsatile, non-tender, and deep seated but mobile, consistent with a lipoma. Radiographic images were taken preoperatively that demonstrated a bony exostosis on the volar aspect of the left fifth digit connecting the middle and proximal phalanx at the PIPJ that was likely contributing to the severity of the contracture (Figure 1).

OPEN IN VIEWER

Figure 1.

Preoperative X-ray of the patient’s 90° contracture of the left little finger proximal interphalangeal joint with visible bone formation approximately 1.5 cm in length.

The left finger was explored in the operating room under regional anaesthetic with tourniquet control. The left thenar eminence mass was dissected from overlying digital nerves and removed in toto. Inspection of the mass was consistent with the preoperative diagnosis of a lipoma. The left little finger was approached using the previous incisions overlying the PIPJ and metacarpophalangeal joint. Radial and ulnar skin flaps were raised overlying the diseased tissue, leaving thinned skin flaps as the disease was adherent secondary to the recurrent nature. The disease surrounding the radial neurovascular bundle was removed first, but the PIPJ contracture was not passively correctible after removal. The ulnar neurovascular bundle was then traced from proximal to distal and the bony bar was encountered around the level of the proximal aspect of the proximal phalanx. This bony exostosis was observed to be covering the ulnar neurovascular bundle, but was separate from it. The bone was released at its proximal attachment to the proximal phalanx, and a tissue plane was present between it and the neurovascular bundle. The bony exostosis was lifted from proximal to distal and an osteotome was used to release the remaining connection to the PIPJ as it was adherent to the middle phalanx. The bony growth of approximately 1.50 cm was removed and sent for pathology (Figure 2). Once the bony growth was removed, the PIPJ contracture was able to be corrected passively. The remainder of the Dupuytren disease was then removed around the ulnar neurovascular bundle distally; hemostasis was obtained and the skin was closed with Z-plasties.

OPEN IN VIEWER

Figure 2.

Clinical picture of the heterotopic ossification removed from the volar aspect of the patient’s left little finger proximal interphalangeal joint. The lesion measures approximately 1.5 cm.

Pathology reports following the operation revealed that the thenar mass was benign mature adipose tissue, or lipoma, as suspected. Sections of the bony growth were consistent with reactive changes leading to exostosis or HO. The dense fibrous tissue removed from the area surrounding the PIPJ was found to be superficial palmar fibromatosis, as is the case of Dupuytren disease.

Discussion

To the best of our knowledge, only one other case of Dupuytren contracture with bony exostosis has been reported ¹ ; however, no preoperative radiographic images were available in that report as it was discovered intraoperatively. Similar to the previous case, ¹ the heterotopic ossified lesion identified was within the Dupuytren contracture and seemed to be the principal reason for the recurrent contracture. We were fortunate to have taken preoperative radiographs identifying the HO prior to surgical excision. The bony growth that extended between the middle and proximal phalanx at the PIPJ was determined histologically to be HO, distinct from typical calcification or osteophytes seen with Dupuytren disease in other case reports. The PIPJ contracture was only corrected once the HO was removed. Like the previous report, our patient did not have any connective tissue disorder, hyperparathyroidism, or metastatic calcification.

Despite ongoing research, ² the exact cause of HO remains unknown. A recent studying examining elbow trauma revealed that male gender was a significant risk factor for HO, ⁷ perhaps due to differences in hormonal signalling and osteogenesis. The incidence of HO development in hip arthroplasty is reported as high as 5% ⁸ ; however, the incidence of this condition in relation to hand conditions remains unknown due to the rarity of reported cases.

We report the second documented case of HO from within a Dupuytren contracture, adding to the evidence that HO may develop in long-standing Dupuytren disease. This HO may be the cause of the recurrent contracture and must be removed along with the recurrent disease to correct the joint deformity. As our patient was healthy otherwise, recurrent trauma to his fifth digit due to the contracture, as well as his male gender, may have contributed to the development of this lesion. It is important for hand surgeons to recognize that although rare, this phenomenon may occur and therefore appropriate surgical planning to avoid potential complications of HO in long-standing Dupuytren must be considered. Given the rarity of this condition, prophylaxis for HO preoperatively is likely unnecessary and may be associated with added morbidity.