METATARSALGIA
Jun 01, 2015
METATARSALGIA
CLASSIFICATION
• Primary
• Secondary
• Metatarsalgia unrelated to disorders of weight distribution
PRIMARY METATARSALGIa• Due to c/c imbalance in wt distribution b/w the toes
& the metatarsal headsCauses a) Static:
Funtional: tight pointed shoes with a high heel, obesity Structural:
Overload & insufficiency syndromes Long first metatarsal Short first metatarsal Metatarsus primus varus Synostosis b/w metatarsals Length discrepency b/w metatarsals Pes cavus Toe abnormalities
b) Hallux valgus
c) Hallux rigidus
d) Iatrogenic
e) Traumatic
f) Freiberg’s disease
g) Morton’s neuroma
Secondary metatarsalgia1. Rhematoid disease
2. Sesamoiditis
3. Post traumatic
4. Neurogenic
5. Stress #
6. Gout
7. Short limb
Metatarsalgia unrelated to disorders of weight distribution
• Neurological Spine Tarsal tunnel syndrome Anterior tarsal tunnel syndrome
• Vascular insufficiency Peripheral vascular disease Diabetes
FREIBERG’S DISEASE
INTRODUCTION• In 1914, Alfred H. Freiberg first described the
painful collapse of the articular surface of the second metatarsal head.
• Usually affects the second metatarsal
• MC recognized in the second decade of life
• More frequent in girls
• Can be b/l
ETIOLOGY & PATHOGENESIS• Freiberg disease in adolescents is thought to belong to
a group of related diseases involving growth disturbances of the epiphysis or apophysis, collectively termed the osteochondroses.
• Of all the osteochondroses, Freiberg disease is reported to be the fourth most common, exceeded by Köhler disease of the tarsal navicular, Panner disease of the capitullum, and Sever disease of the calcaneus.
• Radiographic changes among the osteochondroses are similar, regardless of location; they show subchondral collapse and fragmentation of the joint surface.
• It does not fully explain the adult onset form of the disease, which may represent a different process altogether
Vascular insult• Radiographic changes that are consistent with
avascular necrosis have led some authors to suggest that the inciting event is an injury to the blood supply to the metatarsal head.
• vascular supply to the metatarsal heads can be quite variable.
• the second and third metatarsals receive a less consistent blood supply than do the other metatarsals.
• Iatrogenic avascular necrosis of the second and third metatarsal heads following elective forefoot surgery as indirect evidence that a disturbed blood supply may be at least partially responsible for the development of Freiberg disease.
Traumatic insult• may be in the form of a single acute injury or
multiple repetitive microinjuries.• Freiberg postulated that a long second metatarsal
in combination with altered first ray mechanics eventually leads to overload of the second
metatarsophalangeal (MTP) joint.• Of the metatarsals, the second and third are the
least mobile.• the second and third metatarsals, because of their
relative inflexibility and increased load transmission, are at increased risk of sustaining repetitive microtrauma.
• Smillie considered Freiberg disease to be a repetitive stress injury, analogous to a march or stress fracture.
• He believed that concentration of stress in the trabecular bone at the dorsal aspect of the metatarsal head eventually leads to collapse.
• typical location of the lesions can be explained on the basis of mechanical impingement between the base of the proximal phalanx and the dorsum of the metatarsal head in forced dorsiflexion.
• Trauma to the metatarsal heads as an indirect result of a peripheral neuropathy could result in the development of Freiberg disease.
• Intrinsic motor weakness, as is often seen with peripheral neuropathy, can lead to extension of the toes at the MTP joint, resulting in an increase in weight bearing by the metatarsal heads, repetitive injury, and subsequent collapse.
• In summary, the exact nature of the etiology of Freiberg disease is unknown.
• It is most likely a multifactorial etiology that includes vascular and traumatic insults.
• Certain patients may be anatomically predisposed based on local mechanical, vascular, and developmental factors.
• The relative infrequency of the disease, as well as the variable presentation regarding age and injury, makes the study of various etiologies challenging.
SYMPTOMS & SIGNS• Pain about the involved MTP joint primarily on
weight bearing
• Local tenderness about the MTP joint
• Limitation of movements
• If synovitis +, swelling
Imaging studies
Smillie's classification
STAGE 1 Fissure fracture of the ischemic epiphysis
STAGE 2 Central depression of the head from bone resorption
STAGE 3
Further collapse of the head with residual projections of the sides
STAGE 4 A portion of articular cartilage separates into a loose body
STAGE 5 Arthritis, deformity, and flattening of the metatarsal head
Early stage I
Stage II lesion with resorption of subchondral cancellous bone
Smillie's classification
STAGE 1 Fissure fracture of the ischemic epiphysis
STAGE 2 Central depression of the head from bone resorption
STAGE 3
Further collapse of the head with residual projections of the sides
STAGE 4 A portion of articular cartilage separates into a loose body
STAGE 5 Arthritis, deformity, and flattening of the metatarsal head
Stage III with collapse of the head with residual projection
of the sides
Smillie's classification
STAGE 1 Fissure fracture of the ischemic epiphysis
STAGE 2 Central depression of the head from bone resorption
STAGE 3
Further collapse of the head with residual projections of the sides
STAGE 4 A portion of articular cartilage separates into a loose body
STAGE 5 Arthritis, deformity, and flattening of the metatarsal head
Stage IV lesion with articular collapse and loose body formation
Stage V lesion with advanced degenerative changes involving the
metatarsal head and proximal phalanx
TREATMENTCONSERVATIVE MANAGEMENT• Goal - to rest the joint to allow inflammation and
mechanical irritation to resolve.• In patients presenting with severe pain of an acute
nature, a non – weight-bearing cast may provide sufficient relief during the acute phase.
• a short leg walking cast may be more appropriate• In patients with chronic complaints, less restrictive
options, such as shoe modifications in the form of inserts with metatarsal bars or pads, rigid shanks, or a rocker bottom, may be helpful.
• Activity modification during exacerbations may help to prevent the aggravating symptoms of pain and swelling.
Surgical treatment While some stage I, stage II, and stage III
lesions may resolve spontaneously, patients who do not respond to conservative measures and patients with stage IV and stage V lesions may require surgery.
SURGICAL OPTIONS1. Resection of the metatarsal head2. Elevation of the depressed fragments of the
metatarsal head & bone grafting of the defect3. Resection of the base of the proximal phalanx with
syndactilization of the 2nd & 3rd toes4. Dorsal closing wedge osteotomy of the
metatarsal head5. Joint debridement & metatarsal head
remodelling 6. Total joint arthroplasty
The patient must be informed before Sx some permanent limitation of motion is usual. Since motion in the affected joint is frequently limited anyway, this is not a deterrent to Sx.
Metatarsal bars or pads should be used for 3-6months after Sx.
JOINT DEBRIDEMENT & METATARSAL HEAD REMODELLING
• Angled incision• Expose the extensor hood• Expose the entire extensor expansion over the
MTP joint• Identify the EDB as it joins the EDL & section the
former at its juncture• Incise the extensor hood just lateral to the EDL &
retract the tendon medially• Through a longitudinal capsulotomy enter the
MTP joint & reflect the capsule medially & laterally by sharp dissection
• Remove all the osteochondral fragments• Distract the toe manually-expose the MT head
RELATION OF EXTENSOR
TENDONS TO THE MTP JOINT
• If the articular surface has remodelled, debride the joint of all loose fragments, remove the synovium & perform a Z-plasty lengthening of the EDL.
• If the MT head is pitted, contour it.• The surface of the MT head usually is depressed
dorsally & centrally-round the remainder which usually requires 3-4mm of bone removal circumferentially.
• Irrigate the joint while flexing & extending it to flush any remaining cartilage or bony fragments.
• Close the capsule with fine absorbable sutures & apply a dressing that holds the joint reduced.
After Surgery• Elevate the foot for 48hrs
• Followed by walking in a wooden-sole shoe
• At 2 weeks, SR
• The forefoot is redressed , holding the toe in desired position
• At 4 weeks, toe-box shoe is allowed & gentle active assisted ROM of the 2nd MTP joint is encouraged
Dorsal Closing Wedge Osteotomy • A gently curved dorsal incision over the head of
the metatarsal
• The joint is debrided, and any loose bodies or hypertrophic synovium removed
• To avoid aseptic necrosis and nonunion complications removal of soft tissue is avoided as much as possible.
•A dorsal wedge is removed from the normal dorsal metaphysis.•Internal fixation is performed with a figure of (8) stainless steel wire loop or •stabilized with K-wire
AFTER SURGERY
• A walking cast with a toe platform is applied. • Stitches were removed at 2 weeks• The cast discarded at 4 weeks.• The patients were instructed to use soft shoes
and avoid strenuous activities for another 4 weeks.
MORTON’S NEUROMA
• In 1876, Thomas.G.Morton described a condition of pinching of the common digital branch of the lateral plantar nerve in the 4th web space b/w the mobile 4th to 5th MT heads of the foot.
Pathogenesis1.Pinching of the common digital branch of the
lateral plantar nerve in the 4th web space b/w the mobile 4th to 5th MT heads of the foot.
2.Laxity of transverse metatarsal ligament that allows a break in the anterior arch with plantar displacement of central MT heads & pressure on adjacent digital nerve
3. Instability of the fourth MTP joint
4. Development of pressure neuralgia from pressure on the nerve during weight bearing
5.Flattening or falling of the transverse arch that results in excessive pressure over the central MT heads.
6.A tumor involving lateral most branch of medial plantar nerve.
7. Lumen occlusion of the common digital artery adjacent to the nerve.
8. The fourth digital branch of medial plantar nerve which receives a communicating branch from common digital branch of lateral plantar nerve. Becoz of this additional branch, common digital nerve to third web space is thicker & more likely to be compressed against the unyielding deep transverse intermetatarsal ligament dorsal to it.
None if the theories has been universally accepted.
Pathology• Neuroma is a misnomer• Deposition of hyaline & collagenous material
Findings:Perineural fibrosisIncreased no: of intrafascicular arterioles with thickened &
hyalinized walls caused by multiple layers of basement membranes
Demyelination & degeneration of nerve fibres with a decrease in the no: of axon cylinders
Endoneural oedemaAbsence of inflammatory changesFrequent presence of bursal tissue accompanying the
specimenObliterative changes in the contiguous artery of most
unusual type & debatable origin
CLINICAL FEATURES
• Females are MC affected• Age :20-50yrs• Unilateral• Pain in the region of the MT heads, usually
the 3rd & 4th
• Burning, aching or cramping• Aggravating & relieving factors• The most frequent site of tenderness is in the
3rd web space just distal to the transverse intermetatarsal ligament.
TESTSMULDER’S CLICK
A palpable & audible click may be appreciated when the patient lies prone & the examiner places the thumb dorsally & the index finger plantarward over the appropriate web space & gently rocks the hand back & forth.
EXTENSION TEST Passively extend the MTP joints.
This tightens the ligament & compresses the nerve.
TREATMENTNON OPERATIVE RX metatarsal bars & pads, local inj. of a
steroid preparation into the web space, wide toe box shoes
SURGICAL RX Excision of the neuroma-dorsal or
plantar approach Neurolysis
TECHNIQUE• Calf tourniquet. • Dorsal longitudinal incision 3cm proximal to the
web space & extend it distally, ending just proximal to the web space.
• Fascia released over the intermetatarsal ligament
• Intermetatarsal ligament transected with a freer elevator placed underneath the ligament to protect the underyling structures
• Dorsally directed pressure under the area aids
exposure of the neuroma
• Fine right angle hemostat is utilized to free the nerve and expose the bifucation.
• Gentle pressure is placed on the proper nerve and the nerve is then transected proximally
• Specimen is sent for histologic examination. • Area is copiously irrigated.
• Tourniquet released, hemostasis obtained
• Closure
DORSAL APPROACH
• The nerve is better exposed in its proximal
portion• In recurrent interdigital neuroma, it is difficult to
find the stump of the nerve in the scar tissue
plantar approach
• Gives excellent exposure in recurrent IDN• The nerve is transected as far as possible as the
incision allows.
After Sx• For 48hrs, the patient rests with maximum
elevation of the extremity & bathroom privileges only are encouraged.
• Walking is then allowed as tolerated.
• SR at 2-3 weeks & plastic strips are placed across the wound for another week.
• A post op wooden-soled shoe is usually needed for 2-3weeks followed by a wide toe-box shoe for an additional 3-4 weeks.
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