Download 1st CMC arthritis

1st CMC osteoarthritis
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more common in women 5th-7th decade
up to 1/3 of women over age 40, will have x-ray changes
may exist in a localized form or may exists as a systemic form of arthritis;
Pathogenesis
 primary form is most common in post-menopausal women;
 mechanisms
1. Hypermobile MP joint by concentrating forces on the palmar aspect of the
trapeziometacarpal joint. Center of pressure moves dorsally on the TZMJ with
increasing MP flexion.
2. Degeneration of the palmar oblique ligament has been linked to increased
metacarpal translation on the trapezium, causing incongruity and instability of
the first ray and generating abnormal shear forces between the articular
surfaces, with wear of the articular cartilage and progression to osteoarthritis.
The palmar oblique ligament and the first intermetacarpal ligament have been
found to play a primary and secondary role in thumb stability
 systemic form may be due to RA or gout
Clinically
History
 Pain is the predominant symptom
 Aggravated by hand use or activities of daily living.
 Sensation of “slipping” or “moving” in the joint.
 Weakness, dropping of objects.
 Opening a tight jar is usually the most difficult task, followed by buttoning
clothes
 Prominence at MC base.
Examination
 Prominence, subluxation of 1st CMCJ joint (“shoulder sign”).
 Tenderness and / or crepitus over the joint.
 Secondary hyperextension deformity of MP or IP joints.
 Laxity of CMCJ joint (in both planes).
 Crank test:- Axial loading plus circumduction of the thumb reproduces pain
and crepitus.
 Grind test:- Axial loading plus rotation of the thumb reproduces pain and
crepitus.
 determine whether pain is related to instability vs arthrosis
 1st web space cleft angle and span.
 thumb may have adduction deformity (web space contracture)
 hyperextension deformity of MCP joint often follows adduction contracture;
 localized tenderness over volar aspect of thumb;
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when in doubt, a small amount of local anesthetic injected into CMC joint
with a resolution of pain will confirm the diagnosis;
Measure grip and key pinch.
Radiology views
 Pronated AP, oblique, lateral and stress views are done.
 Robert’s hyperpronated view shows all four trapezial facets and the common
trapezio-metacarpal osteophyte. The view is taken with the hand
hyperpronated so that the thumb and index finger rest on the X-Ray plate and
the palm faces upwards and out-wards.
 The true lateral view (sesamoids must overlap) and the oblique view show the
degree of TMJ disease and the palmar beak of the MC.
 Stressed views to look for instability and subluxation are taken of both hands
simultaneously on one film. The radial borders of the thumbs are pushed
together (phalanges, not metacarpals).
Staging (Eaton-Littler, et a 1984)
Determines surgical management and therefore important.
Based on the true lateral X-Ray.
Stage I
 Symptomatic instability with:
1. Normal articular contour
2. Slight widening in joint space - indicates effusion or active synovitis.
3. no subluxation and no osteophyte formation are present;
Stage II
 Slight narrowing of joint space
 Minimal sclerotic changes
 may be osteophyte formation at the ulnar side of the distal trapezial articular
surface;
 mild to moderate suluxation may be present (w/ the base of the first
metacarpal subluxated radially and dorsally);
Stage III
 Joint space markedly narrowed or obliterated
 Cystic changes, sclerotic bone, varying degrees of dorsal subluxation
 prominent osteophytes are present at the ulnar border of the distal trapezium;
 Scaphotrapezial joint appear normal
 moderate suluxation is present w/ the base of the first metacarpal subluxated
radially and dorsally - passive reduction may not be present;
 scaphotrapezial may show arthrosis, and there may be a hyper-extension
deformity of the MTP joint;
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Stage IV
 All the features of stage III disease but with the addition of scapho-trapezial
involvement with joint space narrowing and sclerosis.
 CMC joint is usually immobile and often patients have little pain;
Management
 severity of symptoms of osteoarthritis at the trapeziometacarpal joint does not
necessarily correspond with the radiographic stage of the disease
 the decision to proceed with surgery is determined by the extent that pain and
loss of function interfering with activities of daily living
 Other considerations include the patient's age and specific functional demands.
Conservative
1. therapeutic heat and massage
2. splints designed to reduce the pain and preserve the web space
3. exercise regimens to strengthen the thenar musculature and restore dynamic
stability at the trapeziometacarpal joint
4. anti-inflammatory medications to relieve the pain
5. steroid injections
Surgery
Persistent pain, weakness and instability leads the patient to consider surgery
Treatment by stage of disease
History
o trapeziectomy introduced by Gervis to remove painful arthritic joint surfaces
o Trapeziectomy alone has traditionally been the procedure chosen for the lowdemand elderly patient with more advanced disease
o procedure can result in weakness and instability because it cannot prevent
proximal migration of the first metacarpal, causing impingement between the
metacarpal and scaphoid with loss of length of the thumb ray
o 1983: Burton introduced FCR reconstruction of palmar oblique ligament to
prevent proximal migration
o Biddulph recommended ECRL
o Swanson used silicone rubber implants to prevent proximal migration
o 1986: Burton and Pellegrini modified the technique using the entire FCR length so
that half the tendon can be used as a spacer to avoid use of a silicone implant.
Required use of a K wire for 4 weeks to stabilise the thumb metacarpus to the IF
metacarpus.
Stage I
 Painful instability - have ligamentous laxity resulting in joint space widening, but
normal articular contours.
 Aim: stabilise the joint and attempt to prevent the progression of osteoarthritis.
 Options:
1. volar ligament reconstruction (Eaton 1984)
o Eaton and Littler described a ligament reconstruction with the use of a
strip of the flexor carpi radialis tendon to reinforce the lax palmar oblique
ligament and stabilize the symptomatic hypermobile joint that may delay
progression of osteoarthritis of the thumb basal joint in patients with slight
cartilage attrition
o Brunelli uses a slip of APL (detached proximally and attached to the IF
metacarpal base). Good for early disease with normal joint surfaces.
Intra-operatively, the joint surfaces must be checked to see that they are of
good quality. If they are not, one must be prepared to treat as stage II.
This method of treatment is not used in the rheumatoid as they are prone to
tendon rupture
2. metacarpal osteotomy (Wilson)
o may be performed to redistribute trapeziometacarpal contact area and load,
away from the compromised volar joint surface to the normal dorsal
surface (Hobby 1998).
o Usually the palmar aspect of the CMCJ joint is affected first, the dorsal
aspect being relatively spared. The Wilson’s osteotomy is a closing wedge
osteotomy into 30 more of extension-abduction thus bringing the load of
the joint to the dorsal aspect.
o The operation is best for the labourer who has a high demand hand. Does
not preclude later arthrodesis or arthroplasty.
o has been found to be an effective biomechanical alternative to ligament
reconstruction in people with Eaton Stage I osteoarthritis
Stage 2
 early degenerative changes to the trapeziometacarpal joint
 choice of surgical procedure is likely to be influenced by the severity of their
symptoms and their functional demands
 Options:
1. volar ligament reconstruction
2. metacarpal osteotomy
 reported to provide lasting pain relief, correct any adduction
contracture and restore strength
3. trapeziometacarpal arthrodesis
 most indicated for painful instability (especially w/ sytemic
hyperlaxity), and indicated for a young active male with isolated CMC
arthrosis (and absence of arthrosis in adjacent joints);
 thumb metacarpal is held in 30-40 deg palmar abduction and 10-15 deg
of radial abduction;
 disadvantages:
i. Results in significant loss of motion at the base of the thumb
and has been associated with compensatory hyperextension
at the metacarpophalangeal joint
ii. Stressed may be transferred to other joints which may then
develop OA.
iii. significantly high rate of non union (upto 50%)
iv. need for prolonged postoperative casting
4. partial trapeziectomy
5. interpositional arthroplasty
 Trapeziectomy with ligament reconstruction and tendon interposition
(LRTI) was found to improve strength and restore web space, however
the potential for recession of the metacarpal and instability at the
pseudoarthrosis site remains a concern
 Trapeziectomy may be partial in stage II disease. Diagram below is the
LifeSaver technique by
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6. trapeziometacarpal joint replacement.
 Replacement of the degenerative articular joint surface with a
prosthesis has the potential to reproduce normal kinematics and
stability at the joint in the presence of intact ligaments, but
unfortunately these prostheses have problems - subluxation and
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instability; fracture and fragmentation; silicone synovitis; prone to loss
of height with wear and tear.
main problem is instability and dislocation of prosthesis (may occur in
40 % of thumb
Silicone implants are therefore only recommended for the low demand
hand.
Stage 3
 advanced degenerative changes at the trapeziometacarpal joint, with marked
joint space narrowing, joint debris and subluxation, and significantly greater
trapezial tilt than people with Eaton Stage I or II
 Similar options as above
 Trapeziectomy with ligament reconstruction ± tendon interposition (LRTI) has
become the preferred method of treatment.
 Epping and Noack introduced trapezial excision with suspensory FCR
ligament reconstruction to reinforce the first intermetacarpal ligament.
o The Burton-Pellegrini operation adds interpositional arthroplasty using
FCR although other tendons have been described (APL, ECRL).
Stage 4
 need a procedure which adequately addresses pain arising from both the
trapeziometacarpal and STT joints.
 Options:
2. trapeziectomy
3. trapeziectomy with LRTI
4. trapeziometacarpal and STT joint replacements.
o double interposition joint replacement (Barron 1998) replaces both the
trapeziometacarpal and STT joints
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Best treated by excision of whole trapezium and replacement arthroplasty.
Silicone can be used in the low demand hand (patient > 65 years), otherwise
LRTI. Arthrodesis is also an option.
Outcome (Cochrane metanalysis)
 there is sufficient evidence to conclude that no one procedure produces greater
benefits in terms of strength than any other
 trapeziectomy is safer and has fewer complications than trapeziectomy with
ligament reconstruction and tendon interposition or trapeziectomy with
interpositional arthroplasty.
 trapeziectomy with LRTI has more adverse effects than trapeziectomy,
trapeziectomy with interpositional arthroplasty, and trapeziectomy with
ligament reconstruction.
 Therefore, unless there are strong indications to do otherwise, trapeziectomy
alone should be used because it achieves good outcomes (as good as the other
procedures) and it has fewer adverse effects. Similarly, unless there are strong
indications to do otherwise, trapeziectomy with LRTI should be avoided
because it causes more adverse effects.
Other Procedures
1. MCPJ Hyperextension
 Less than 30
a. Transarticular K-Wire with joint in flexion for 4-5 weeks
b. Moving the extensor pollicis brevis from base of proximal phalanx to
metacarpal shaft
 Greater than 30
a. Arthrodesis (unstable joint)
b. Volar capsulodesis
Surgical Methods
 trapeziometacarpal joint exposed through a dorsoradial hockey-stick-shaped
incision over the base of the thumb.
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Care was taken to avoid injury to the superficial branch of the radial sensory
nerve and the radial artery.
Trapeziometacarpal joint is exposed through a longitudinal incision
between the extensor pollicis brevis and the abductor pollicis longus
tendons.
The entire trapezium is excised and then converted, with the use of rongeurs,
to corticocancellous and cancellous bone chips.
In LR only, FCR is harvested with the wrist flexed and in the depth of the
trapezial void, with its insertion left intact on the base of the index metacarpal.
The distally based strip of the flexor carpi radialis tendon was routed through
an oblique canal in the first metacarpal base, which had been created with a
3.2-mm burr. The canal began dorsoradially at a distance of approximately 1
cm from the metacarpal base and ran in a palmar-ulnar direction through the
articular surface of the metacarpal base.
In LRTI, the radial half of the flexor carpi radialis tendon was harvested
proximally through a second longitudinal incision in the forearm. The tendon
strip was drawn through the bone canal, blocked by bone chips as it was in the
other group, and sutured to the surrounding periosteum. The remainder of the
tendon was rolled up, placed into the trapezial void to act as a spacer, and
fixed with a 4-0 absorbable suture to the flexor carpi radialis tendon in the
depth of the arthroplasty space
Half of the flexor carpi radialis (FCR) tendon is passed through a canal in the articular
surface of the metacarpal base from palmar-ulnar to dorsoradial. I = first metacarpal,
and II = second metacarpal.
Half of the flexor carpi radialis (FCR) tendon is rolled to form a tendon arthroplasty
spacer that is placed into the space created by removal of the trapezium. I = first
metacarpal, and II = second metacarpal.