Phalangeal Reaming and Irrigation for Combined Proximal and Distal Phalangeal Osteomyelitis of the Thumb

Abstract

Acute and chronic osteomyelitis of the phalanges may lead to digital amputation because of the difficulty of adequately debriding infected tissue, while concurrently maintaining the delicate function of the digit. In our patient with osteomyelitis of the proximal and distal thumb phalanges as well as the adjoining interphalangeal joint, we used a reamer-irrigator-aspiration system, commonly used in nonunion and long bone osteomyelitis, to effectively ream the intramedullary canals of the phalanges. This allowed for adequate debridement and irrigation of our patient’s deep space infection using a minimally invasive approach, while avoiding more extensive debridement or amputation. After completion of 6 weeks of intravenous antibiotics, this patient successfully cleared the osteomyelitis while maintaining the function of her thumb.

Osteomyelitis is a notoriously difficult problem that remains difficult to treat despite advancements in antibiotics and surgical technique. Microbes are able to find refuge from the body’s immune system as they can create a sequestrum within the bone, where there is poor blood supply and a physical barrier in the cortex of the bone.

The challenges of treating osteomyelitis can be amplified in the phalanges because of lack of bone stock and the close proximity to multiple joints that can lead to septic arthritis and spread to adjacent phalanges. After multiple failed attempts to clear the infection through surgical debridement, it is not uncommon for the phalangeal segment to be amputated to prevent further spread within the hand.¹

The following case report uses the principles of the reamer-irrigator-aspiration system, which is commonly used in nonunion and osteomyelitis cases of long bones.^2,3 In this case, we treat osteomyelitis in the finger by “reaming” the intramedullary canal with a drill bit and then creating a counter incision and corticotomy in order to allow adequate irrigation of the intramedullary canals.

Case Report

A 75-year-old right-handed woman with a past medical history of breast cancer treated with radiation and bilateral mastectomy eleven years prior presented with concern for right thumb osteomyelitis and interphalangeal joint septic arthritis. The patient had undergone an elective excision of a symptomatic interphalangeal (IP) joint mucous cyst approximately 6 weeks prior at an outside facility. This surgery was complicated by a deep space infection leading to a pattern of right thumb IP joint septic arthritis. At the original facility, she underwent a limited surgical debridement through a dorsal approach to the IP joint 4weeks after her index surgery with no documented evacuation of purulent discharge and negative cultures. The patient was given an antibiotic course of trimethoprim–sulfamethoxazole for persistent pain, swelling, cellulitis, and drainage from the original provider. She presented to our institution with x-rays and a magnetic resonance imaging concerning for right thumb proximal and distal phalanx osteomyelitis in conjunction with her IP joint septic arthritis (Fig. 1A–D). Her inflammatory markers were elevated with a white blood cell count of 6.01 × 10⁹/L, C-reactive protein level of 6.7 mg/dL, and erythrocyte sedimentation rate of 47 mm/hr. This composition of clinical presentation, laboratory results, and imaging led us to a diagnosis of right thumb proximal and distal phalanx osteomyelitis. After discussing the potential for persistent infection, stiffness, and future surgeries including possible arthrodesis or amputation because of the nature of osteomyelitis, the patient elected to proceed with irrigation and debridement of her distal and proximal phalanx.

Figure 1.

Osteomyelitis of the proximal and distal thumb phalanges. A Preoperative posteroanterior hand x-ray. B Preoperative lateral hand x-ray. C Preoperative T2 STIR sagittal MRI. D Preoperative T2 STIR coronal MRI revealing. MRI, magnetic resonance imaging; STIR, short tau inversion recovery.

The procedure began with superficial debridement of the cutaneous tissues, which had multiple areas of accumulated eschar over the prior surgical scars and retained nylon sutures.

Next, we proceeded to ream the intramedullary canals of both the distal and proximal phalanges of the thumb. This was performed by first introducing an intramedullary Kirschner wire corresponding to a cannulated 2.7 mm drill bit in retrograde fashion starting at the distal aspect of the distal phalanx, crossing the thumb IP joint, and then continuing into the thumb proximal phalanx, terminating in the subchondral bone at its base (Fig. 2A). A 2.7-mm drill bit was selected after using preoperative measurements and confirming under intraoperative fluoroscopy that the reamer would fill the endosteal canals of the affected phalangeal segments to create effective internal mechanical debridement. Careful attention was paid to preserve a collinear relationship between the endosteal canal of the distal phalanx and the endosteal canal of the proximal phalanx. Fluoroscopy was used to confirm appropriate placement of the Kirschner wire. Next, we made a small opening skin incision at the distal aspect of the thumb to accommodate the 2.7 mm cannulated drill, which was instrumented over the Kirschner wire to ream the intramedullary canals of both the distal and proximal phalanges (Fig. 2B). The reamings were found to have consolidated purulence. Great care was taken not to penetrate the metacarpophalangeal joint to avoid any potential seeding of infection.

Figure 2.

A Fluoroscopy image demonstrating insertion of the retrograde Kirschner wire through the apex of the distal phalanx, across the interphalangeal joint, and into the base of the proximal phalange. B Cannulated reaming of the thumb distal and proximal phalanges. C Creation of a radial corticotomy for the outflow portal at the thumb proximal phalanx base. D Retrograde irrigation through an intramedullary angiocatheter with the resultant irrigant expelling out the outflow portal at the proximal phalanx base.

A small longitudinal mid-axial incision was then made over the radial base of the thumb proximal phalanx. Blunt dissection was carried down to bone, and the neurovascular bundle was identified and retracted volarly. A similar 2.7 mm corticotomy was rendered at the base of the thumb proximal phalanx in a distal trajectory using the drill bit to create an outflow portal for irrigation of the canals (Fig. 2C). The bone in this area was noted to be compromised with respect to integrity secondary to osteomyelitis. A 16-gauge Angiocath, with the needle within the Angiocath, was then placed into the intramedullary canal of the distal phalanx. The needle was subsequently removed and the intramedullary canals of both the distal and proximal phalanx intramedullary canals were irrigated with serial 30 mL flushes (500 mL in total), with excellent flow through both intramedullary spaces and easy expression out the outflow portal at the base of the thumb proximal phalanx (Fig. 2D; Video S1, available online on the Journal’s website at https://www.jhsgo.org). The initial flush was noted to have thick purulence consistent with acute osteomyelitis.

The Angiocath was removed, the proximal counter incision was loosely closed with simple 4-0 nylon sutures and the distal incision was left open to drain over the tip of the thumb pulp. The wound was dressed with xeroform, bacitracin, and gauze.

The patient was discharged on postoperative day 2 after receiving a peripherally inserted central catheter line with an antibiotic regimen of oral doxycycline and intravenous ertapenem, which was later changed to intravenous daptomycin and ertapenem by an external infectious disease physician. She completed 6 total weeks of intravenous antibiotics. Her intraoperative cultures from our institution were negative for aerobic organisms at 3 days and anaerobes at 5 days. At her 2-week, 4-week, and 7-week postoperative appointments, the patient noted continual improvement in her pain and range of motion. At her final clinic visit 3.5 months after surgery she had completed her antibiotic course 8 weeks prior. The patient’s inflammatory laboratory results had completely normalized with her C-reactive protein level <3 mg/dL and white blood cell count 4 × 10⁹/L. Radiographs of the right hand demonstrated joint space loss of the IP joint and subchondral cyst formation without further erosive changes (Fig. 3A,B). On examination, all erythema, edema and incisional tenderness had resolved with a healed incision over the mid-axial border of the digit. The patient did have stiffness at the IP joint with an active and passive IP joint motion limited to a 10° flexion and extension arc. Active flexion of the thumb MP joint to 45° with full extension of the thumb MP joint was observed (Fig. 4A–C). She did not have any functional pain from her IP joint degenerative changes and was discharged from clinic at this point.

Figure 3.

Final images at 3.5 months after surgery. A Posteroanterior hand x-ray. B Lateral hand x-ray.

Figure 4.

Final clinical images 3.5 months after surgery. A Combined thumb MCP and IP joint extension. B Combined thumb MCP and IP joint flexion for terminal opposition. C Healed incision. MCP, metacarpophalangeal.

Discussion

Osteomyelitis is a difficult problem to address as the surgeon must delicately balance adequate resection of the infected bone while preserving the integrity and function of the skeletal structure. Two techniques have been described to attempt to salvage the phalanges after thorough debridement including permanent antibiotic spacer after open resection and a mini-masquelet technique.^1,4, 5, 6, 7 Although both are attractive salvage options for the phalanges, both require considerable dissection and these techniques preclude preservation of the native IP joints. In our patient, we aspired to preserve the thumb IP joint from resection, although the providers certainly anticipated and counseled the patient regarding the likelihood of IP joint stiffness and even possible definitive arthrodesis moving forward.

Long bone osteomyelitis is often treated with similar local debridement and excision of the necrotic/infected bone followed by a Masquelet technique. In the early 2000’s, Depuy Synthes brought the Reamer-Irrigator-Aspirator (RIA) to market, which was intended to help prevent thermal necrosis and fat embolisms and lessen the systemic inflammatory process of reaming.⁸ It was quickly realized that the RIA could be used in nonunion cases as a source of bone graft and as a way to debride osteomyelitis in long bones.^2,3 Reamer-Irrigator-Aspirator combines the mechanical debridement from the reamer, to help disrupt any involucrums, with irrigation to help remove the infection from the medullary canal. Furthermore, it is hypothesized that reaming the canals of the bone helps to revascularize the bone, allowing for better antibiotic delivery to the bone.³ Multiple studies have found promising results with RIA for osteomyelitis and some have gone on to add the use of an antibiotic coated nail to their treatment to allow for local antibiotic delivery at the infection site.^2,3,9, 10, 11

Indications for phalangeal reaming and irrigation should be limited to osteomyelitis in the distal and middle phalanx for the finger digits and/or the distal and proximal phalanx for the thumb digits when the intervening joint is known to be affected by pyogenic arthritis. The authors would not use this for the proximal interphalangeal joint or the metacarpophalangeal joint because it is not possible to perform a linear reaming technique without seeding the adjacent aseptic joints. It is clinically inappropriate to use this technique if the joint remains aseptic or if the osteomyelitis is limited only to a single adjacent phalangeal segment. In the absence of septic arthritis, phalangeal osteomyelitis can be addressed through a pair of extra-articular corticotomies to produce a similar irrigation opportunity.

Risks of phalangeal reaming and irrigation for combined proximal and distal phalangeal osteomyelitis include joint degeneration, stiffness, and increased risk of fracture and contamination. Stiffness is an expected outcome of this technique, but is acceptable given the fact that the standard distal interphalangeal arthrodesis is well tolerated.

This case demonstrates that applying the RIA concept to phalangeal osteomyelitis treatment allows for a minimally invasive method that preserves the joints, minimizes soft tissue dissection, and potentially increases vascularity to the bone for healing and antibiotic delivery. This technique was able to be applied in a transarticular fashion in the present case as the thumb IP joint was the originally source of infection and it was primarily affected with septic arthritis. The patient was followed clinically and radiographically as well as laboratory values. Resolution of the infection was noted at 3.5 months following surgical treatment.

Conflicts of Interest

No benefits in any form have been received or will be received related directly to this article.

Supplementary Data

Video S1

Video demonstrating retrograde intramedullary and trans-articular irrigation beginning at the distal aspect of the distal phalanx and expressing out the base of the thumb proximal phalanx.