Evaluation of Hemi-implant in Patients with Hallux Valgus and/or Hallux Limitus/Rigidus Anish Amin DPM, Hau Pham DPM, Justin Ogbonna DPM, David Negron DPM, Ewald Mendeszoon DPM, Wei Tseng DPM, Elizabeth Sanders DPM, Vitaliy Volansky DPM Boston University School of Medicine and Boston Medical Center BACKGROUND PURPOSE & HYPOTHESIS RESULTS

Hallux limitus is defined as a decrease in sagittal plane The purpose of the study is to evaluate long term follow up on patients There were 60 patients evaluated, 35 females and 25 dorsiflexion of the hallux at the first metatarsophalangeal who had hemi-implants for correction of hallux valgus and/or hallux males. The average age was 60 ± 11 ranging from 32 joint (MPJ) when the foot is in a weightbearing or limitus/rigidus and whether range of motion and pain relief were sustained to 87 years of age. simulated weightbearing position. Structural hallux within 12 months post-op. limitus is a decrease in joint motion in the loaded and unloaded foot. Functional hallux limitus is a limitation . v 17 patients had moderate bunion with moderate to only when the foot is weightbearing or in the loaded METHODS severe arthritis. position2. Hallux rigidus is referred to as the end stage v 43 Patients had hallux limitus/rigidus (18 grade II, 12 grade III, 13 grade IV) of hallux limitus, when motion is absent or severely restricted to the point of near ankylosis. A retrospective review of 60 patients was performed for patients who v The majority of patients (52) had improvement in received the hemi-implant to the base of hallux proximal phalange. The pain and/or range of motion at the first MPJ after Several grading systems exist for classification of hallux improvement of pain and range of motion after surgery was evaluated. surgery. limitus to assist with dictating treatment. A four-staged Complications including the need to convert to an arthrodesis were also v 8 patients continued to have pain and stiffness within classification that is commonly utilized is as follows: evaluated. a 12 month follow up period of which 3 patients were revised with arthrodesis of the first MPJ. Grade I: limited motion of the first MPJ, mild pain, no significant degenerative joint disease (DJD), minimal osteophyte formation. CONCLUSION Grade II: limited motion, pain, early DJD, osteophyte formation. Grade III: limited motion, pain, DJD, osteophyte The hemi-implant procedure is a joint-preserving formation. surgical technique for patients who have exhausted Grade IV: joint ankylosis, pain, end stage DJD. conservative measures. Out of 60 patients, 8 patients continued to have pain and/or stiffness after surgery. Conservative treatment options for hallux limitus/rigidus Revisional arthrodesis had been performed on 3 include wider shoes, stiff-soled shoes, rocker-bottom patients and may be secondary to varying surgical shoes, orthoses with morton’s extension or metatarsal technique. The remaining 52 patients were found to bars, and intra-articular corticosteroid injections3. have improvement in pain and stiffness and required no Figure 1: Post-operative radiograph revision. The hemi-implant procedure has been shown with hemi-implant in place In the presence of significant degeneration, arthrodesis to be a successful and a durable technique for patients is the most common joint destructive and permanent with hallux valgus and hallux rigidus which allows for procedure with good patient satisfaction. Other joint future arthrodesis if necessary. destructive procedures include 1st MPJ arthroplasty, REFERENCES Keller arthroplasty, total-implant, or hemi-implant (Fig 1. Bouchard, Phillips. “Implants: Total vs. Hemi.” Podiatry Institute Update.1989. 313-320. 2. Franson, Baravarian. “Key Insights On Treating Hallux Limitus.” Podiatry Today. March 2007. 20(3). 1). Total-implants are indicated when there is significant 52 without pain 3. Grady, Axe, Zager, Sheldon. “A Retrospective Analysis of 772 Patients with Hallux Limitis. “Journal of the American Podiatric Medical Association. Feb 2002; 92(2): 102-108. subchondral bone degeneration of both sides of 4. Mann, Clanton. “Hallux Rigidus: Treatment by Cheilectomy.” J Bone Joint Surg Am, 1988 Mar; 70(3): the joint, whereas hemi-implants are indicated when 400-406. 5. Pontell, Gudas. “Retrospective Analysis of Surgical Treatment of Hallux Rigidus/Limitus: Clinical there is significant degenerative change on the base of and Radiographic Follow-up of Hinged, Silastic Implant Arthroplasty and Cheilectomy.” The Journal of Figure 2: Example of hemi-implant. Foot Surgery. 1988, 27(6):503-510. the proximal phalanx and mild change on the head of the 6. Root, Orien, Weed. “Normal and Abnormal Function of the Foot - Clinical Biomechanics. Vol II.” 1 8 continued pain 1977. first metatarsal . 7. Saxena. “The Valenti Procedure for Hallux Limitus/Rigidus.” The Journal of Foot and Ankle *Disclaimer: This is a self supported study, there are no conflicts of interest Surgery.Sept-Oct 1995; 34(5): 485-488.