Management of Chronic Septic Arthritis and Osteomyelitis Following Hallux Valgus Correction With Staged Antibiotic Cement Spacer and Subsequent Bulk Allograft Arthrodesis

Abstract

Case:

A 63-year-old previously healthy woman presented with chronic septic arthritis and osteomyelitis of her first metatarsal and proximal phalanx following attempted hallux valgus correction 4 months prior at an outside institution. Treatment involved culture-directed antibiotics and multiple surgical débridements until bone margins were negative for osteomyelitis. Antibiotic cement spacers were used after surgical débridements to aid with infection clearance and to help preserve first ray length. Definitive surgery was performed once infection was cleared, and the patient ultimately underwent successful bulk allograft first metatarsophalangeal joint arthrodesis. At over one and a half years postoperatively, the patient shows no signs of recurrent infection and ambulates pain-free in regular shoes.

Conclusion:

An antibiotic cement spacer can be considered to help treat first metatarsophalangeal joint chronic septic arthritis and associated osteomyelitis to maintain the length of the first ray before bulk allograft fusion. This case highlights a valuable option for limb salvage in the treatment of complex forefoot infections.

Osteomyelitis of the forefoot, particularly following previous surgical intervention, poses significant challenges. Amputation remains an appropriate treatment strategy for many forefoot infections.¹ However, surgical advances in staged, reconstructive techniques using local antibiotic delivery systems have possibly expanded options for foot-salvage pathways.

Antibiotic cement spacers (ACS) remain a well-defined option in the management of long bone osteomyelitis including the femur and tibia.^2,3 These spacers can serve several roles including delivery of high concentrations of local antibiotics while maintaining bone length before definitive reconstruction. Application of ACS to the foot remains less common in the literature. The anatomic constraints and mechanical demands of the forefoot introduce unique technical considerations when using spacers as a bridge to definitive reconstruction.

This case report describes the successful use of a staged surgical protocol involving an antibiotic cement spacer to manage osteomyelitis following first ray hallux valgus correction. This technique highlights an approach adapted from long bone protocols for limb salvage, which may provide an alternative to amputation in certain complex forefoot infections.

The patient was informed that data concerning the case would be submitted for publication, and she provided consent.

Case Report

This is a 63-year-old woman with a medical history of hypertension and depression who underwent a distal metatarsal osteotomy for symptomatic hallux valgus by a local, nonorthopaedic foot and ankle surgeon. Postoperatively, she reported taking multiple rounds of oral antibiotics because of persistent wound drainage and delayed wound healing. Fifteen weeks after the index operation, she presented to our emergency department with erythema, swelling, and an acutely painful first metatarsophalangeal joint. Figure 1 shows radiographs at initial presentation to our emergency department. She had elevated inflammatory laboratory values (WBC 11.19, CRP 5.5), and an MRI consistent with chronic septic arthritis and osteomyelitis of the first toe metatarsal head, proximal phalanx base, and medial sesamoid. She underwent urgent surgical débridement with the on-call orthopaedic surgeon. Cultures grew methicillin-sensitive Staphylococcus aureus (MSSA), and she was treated with a 6-week course of intravenous (IV) antibiotics as guided by our infectious disease colleagues. Following antibiotics, she was pain-free with healed incisions, and laboratory values were normalizing (WBC 9.53, CRP 1.3).

Figure 1.

Radiographs demonstrating initial presentation to our facility.

Unfortunately, she returned to our emergency department 5 weeks after completing her initial course of IV antibiotics with another episode of acute-onset toe pain, swelling, and generalized malaise. Laboratory values were markedly elevated (WBC 18.30, CRP 4.4, ESR 77), and blood cultures were positive for MSSA. Repeat MRI demonstrated recurrent septic arthritis with a 1.6-cm peripherally enhancing fluid collection at the first metatarsophalangeal joint, as well as osteomyelitis of the proximal phalanx base and the first metatarsal head. She underwent another urgent, repeat surgical débridement with the on-call orthopaedic surgeon. Surgical cultures again returned with MSSA. She was restarted on IV antibiotics, discharged from the hospital, and referred to our orthopaedic foot and ankle division for further management given the complexity of her clinical scenario.

Various treatment options were reviewed with the patient in clinic, including toe salvage versus amputation (which she adamantly refused). To eradicate infection and salvage her toe, she subsequently underwent three additional irrigation and débridement procedures before definitive, bulk allograft fusion. During each of these surgical débridements, bone was resected from the proximal phalanx and the distal metatarsal—and sent for pathologic review and culture evaluation. Intraoperatively, care was taken to resect only the bone that appeared nonviable to minimize the size of the bone defect. At each of these débridements, an antibiotic cement spacer was created (Figure 2). Vancomycin (1 gram) and gentamicin (0.5 grams) laden polymethyl methacrylate (PMMA) cement spacer was shaped and placed over a smooth 3/32 Steinman pin that was placed into the proximal phalanx and distal metatarsal. The toe was then held out to length while the antibiotic-cement hardened to preserve first ray length. The first and second débridements yielded positive culture and margins. Cultures and pathology from the third débridement were negative, which also included medial sesamoid excision.

Figure 2.

Intraoperative radiographs of representative images demonstrating bone void defect (left image) and subsequent antibiotic application spacer application (right image).

At definitive arthrodesis surgery, the static antibiotic spacer was removed, and the ends of the proximal phalanx and metatarsal were freshened again to create punctate bleeding. A bulk allograft bone was used for the first MTP arthrodesis to maintain the length. Allograft bone was used as the patient had concerns regarding donor-site pain from iliac crest autograft harvest. An 18-mm subtalar allograft wedge bone block (Paragon 28) was shaped to fit the defect. The construct was stabilized with a revision MTP bone block plate (Paragon 28) with eccentrically placed screws to aid with bone block compression. (Figure 3).

Figure 3.

Radiographs of final arthrodesis construct with bulk allograft and dorsal plating demonstrating maintained length, alignment, and rotation of the first ray. Raiographs were obtained at nearly 1.5 years postoperatively. Clinically, the patient reports no pain and remains infection free.

Following surgery, she was started on a 2-week doxycycline prophylactic regimen as dictated by our infectious disease team. Cultures and pathology from the definitive bone-block surgery were also negative. She was made non-weight bearing for 10 weeks and then protected weight bearing in a walking boot until week 12 with subsequent transition to regular shoes thereafter. At almost one and a half years postoperatively, she ambulates in regular shoes without pain and has no clinical signs of recurrent infection. Radiographically, the allograft bone shows signs of incorporation within the proximal phalanx and metatarsal and no evidence of implant loosening or failure.

Discussion

Osteomyelitis of the forefoot, particularly following prior osteotomies or surgical correction of deformities, poses a significant challenge. This is due, in part, to the limited soft-tissue envelope. Management in refractory or recurrent infections has often favored amputation, particularly when repeated débridement results in persistent infection. However, evolving techniques in staged infection control, using local antibiotic delivery systems such as antibiotic cement spacers (ACS), may introduce alternative salvage strategies.⁴

Inspired by approaches for managing long bone osteomyelitis, ACS have been used in the foot and ankle to provide local antibiotic concentrations while preserving structural integrity.^3,5 In long bones, ACS is commonly employed as a temporizing measure before second-stage reconstruction, with success rates of bone healing over 80% in some series.⁶ The implementation of ACS in the forefoot has been less well-described. This case report highlights a successful technique using an antibiotic-laden cement to maintain length and alignment while clearing infection before definitive, bone-block fusion surgery.^7-10

Antibiotic cement spacers provide dual benefits in the treatment of foot and ankle osteomyelitis: local, high-dose antibiotic delivery and preservation of soft-tissue length and alignment. The literature on ACS use in the forefoot remains limited. Khury et al.¹¹ showed that 52.7% of patients treated with ACS for diabetic foot osteomyelitis achieved infection eradication without further intervention, while 14.5% succeeded after further follow-up procedures. Woo et al.⁷ and Elmarsafi et al.¹² reported approximately 60 to 66% success rates with around 50 months of follow-up using ACS in the forefoot. The use of dual-agent antibiotic spacers (e.g., gentamicin and vancomycin) has been shown to further reduce the risk of revision surgery compared with single-agent antibiotic spacers, especially in the setting of Staphylococcus aureus infection.^13-15

In the case shown here, key contributors to successful infection clearance included serial surgical débridements, clear negative margins with cultures and pathology before arthrodesis surgery, and collaboration with infectious disease specialists to tailor antibiotic therapy. The use of an ACS in this case not only allowed for high local antibiotic delivery to facilitate infection clearance but also preserved the mechanical length and alignment of the first ray. Once negative margins were confirmed, the foot was reconstructed with bulk structural allograft and plating, which allowed for a durable construct and avoided amputation.

Conclusion

This case report highlights the use of a static antibiotic cement spacer for forefoot osteomyelitis and chronic septic arthritis before bulk allograft arthrodesis. Few studies have described staged reconstitution of forefoot infections. This study highlights a potential option for infection clearance and foot salvage in complex clinical scenarios.