Hallux Rigidus & Silastic Total Implants

Transcription

1 Hallux Rigidus & Silastic Total Implants JOSHUA L. MOORE, DPM FACFAS ASSISTANT DEAN OF EDUCATIONAL AFFAIRS TUSPM CLINICAL ASSISTANT PROFESSOR OF SURGERY

2 Definitions Hallux Limitus 1 st MTPJ range of motion less than 65 degrees in the sagittal plane. Hallux Rigidus - Absent motion of the 1 st MTPJ *Normal gait requires degrees of dorsiflexion.

3 Definitions Functional: Decreased 1 st MTPJ motion when foot loaded or in functioning position. Responds well to orthosis Structural: Decreased hallux motion while foot is loaded or unloaded.

4 Etiology Long 1 st ray 1 st Ray elevatus Hypermobile 1 st ray DJD Septic arthritis Systemic arthridities Weak or absent peroneus longus Iatrogenic Trauma Neoplasms

5 Presentation Pain to joint with palpation & ROM Palpable exostosis 1 st ray elevatus Callus plantar IPJ Metatarsalgia Bursitis to 1 st MTPJ

6 Radiographic findings Flattening of 1 st met head Dorsal exostosis Loose bodies Joint space narrowing 1 st metatarsal elevatus

7 Conservative treatments NSAIDS Injections Physical therapy modalities Orthosis Morton s extension, 1 st ray cut out

8 Surgical considerations Joint salvage Reserved for limitus Excision of ossicles/exostosis Joint destructive

9 Implants Interpositional implant Resection arthroplasty with placement of spacer Total joint replacement Benefits Total resurfacing and joint replacement Immediate weight bearing usually allowed Maintain some function Typically less healing time Room for other procedures in the future

10 Implant Indications/Goals Indications Hallux Rigidus Crepitus & pain with ROM Revisional Surgery Systemic arthridities DJD Osteochondral fractures Goals Reduce pain Gain/Restore motion Correct deformity Long term results Maintain stability

11 Total Implants Hinged silastic Maintains position, stability and motion >30 years of successful clinical outcomes May use grommets to prevent implant breakdown and erosion

12 Pre Op Considerations Patient awareness!! May break down and need replaced or require fusion May have a dull pain May not gain much motion Does the patient have adequate bone stock? Normal alignment of 1 st ray (sagittal and frontal planes) Length of lesser metatarsals

13 Complications Infection Lack of hallux purchase Painful/limited ROM Fracture of metatarsal &/or phalanx Loosening of prosthesis Metatarsalgia Stress fractures lesser metatarsals Interference of sesamoid position and gliding

14 Complications Foreign body reaction Osteolysis Implant destruction Ectopic bone formation Chronic edema Subchondral cysts Telescoping of bone

15 Complications Infection Normally 10 5 whereas with an implant it is 10 2 Reported infection rates from 1-2% Do not let pain and inflammation fool you. Implant destruction Fatigue fracturing implant fractures due to fatigue Breakdown caused by cutting or modifying implant. Subchondral cyst formation 75% of all patients Only problematic if fracture or collapse

16 Complications Reactive synovitis and metallosis Dendritic synovitis!!! Giant cell & inflammatory reaction to silicone. Microfragments formed through abrasion of bone on implant Often require implant removal Ectopic bone formation Bony proliferation around implant Cause limited & painful ROM

17 Pearls Minimal incision for reduced adhesions and scarring dorsally Use of rotary burr to prepare medullary canal Remove a small plantar wedge from metatarsal head Do not touch the implant with your hands Do not cut or compromise the implant Begin immediate weight bearing and ROM exercises Resect as little bone as possible

18 References Morgan S, Ng A, Clough T. The long-term outcome of silastic implant arthroplasty of the first metatarsophalangeal joint: a retrospective analysis of one hundred and eight feet. Int Orthop Sep;36(9): Sullivan MR. Hallux Rigidus: MTP Implant Arthroplasty. Foot Ankle Clin Mar;14(1): Brage ME, Ball ST. Surgical options for salvage of end-stage hallux rigidus. Foot Ankle Clin Mar;7(1): Bonet J, Taylor DT, Lam AT, Williams E, Keane LA. Retrospective analysis of Silastic implant arthroplasty of the first metatarsophalangeal joint. J Foot Ankle Surgery Mar-Apr;37(2): Lemon B, Pupp GR. Long-term efficacy of total SILASTIC implants: a subjective analysis. J Foot Ankle Surgery Sep-Oct;36(5):341-6.