| Abstract|| |
Background: Arthroscopy of the great toe MTP joint has been practiced with favourable outcomes. A range of indications have been described ranging from synovitis to osteochondral defects. The purpose of the present study was to describe our technique and to assess the functional outcome following arthroscopic management of Hallux MTP disorders using AOFAS scoring system.
Methods: We describe the technique of Hallux MTP joint arthroscopy in twenty patients. Indications included hallux rigidus with osteophytes, chondromalacia, OCDs, loose bodies, arthrofibrosis, synovitis, tophaceous gout arthritis and intraarticular fractures of MTP joint. All patients had been evaluated clinically and radiologically with record of their AOFAS scores preoperatively. At a minimum follow-up of two years the clinical assessment was carried out with AOFAS scores.
Results: The mean pre-operative and post-operative AOFAS score were 47 (range 10-78) and 97 (87 -100) respectively. The patient with intra-articular fracture had an excellent outcome following arthroscopic reduction of the fracture.
Conclusion: Arthroscopic management of painful hallucial MTP joint is a specialized technique, which if performed for the right indications, gives a favourable outcome with minimal complications.
Keywords: Arthroscopy; Great toe MTP joint; First metatarsophalangeal joint
|How to cite this article:|
Debnath U K, Hemmady M V, Hariharan K. Arthroscopic management of painful first metatarsophalangeal joint. Indian J Orthop 2005;39:113-6
| Introduction|| |
Arthroscopy of the great toe MTP joint has been practiced in various centres over the last fifteen years for both diagnostic and therapeutic indications. In 1988, Watanabe, Ito and Fuji described the successful arthroscopic management of an osteochondral defect (OCD) of the first metatarsal head  . The technique is demanding and a better understanding of the anatomy and the spatial geometry of the MTP joint is essential for a successful arthroscopy. The indications have been described for the treatment of various conditions of the MTP joint  . The more common ones are, hallux rigidus with osteophytes, chondromalacia, OCDs, loose bodies, arthrofibrosis, and Synovitis ,, . A few available reports in published literature, of arthroscopic treatment of the first MTP joint indicate a favorable outcome  .
We describe our indications and technique for hallux MTP joint arthroscopy. The functional outcome in twenty patients who underwent hallux MTP arthroscopy has been illustrated.
| Material and Methods|| |
Between 1997 and 2003, 20 patients underwent arthroscopy of 25 great toe MTP joints (five patients had bilateral procedures). All cases were performed by the senior author (KH). There were 8 men and 12 women. The mean age at operation was 33 years (range 17 - - 54). Nineteen patients had persistent pain in the hallux MTP joint for a mean duration of 6 months (range 3 - - 12 m) with a mean AOFAS (Hallux MTP-IP) scores of 47 (range 10-78). One patient had arthroscopy assisted treatment of a traumatic intra-articular fracture of the proximal phalanx. Six patients had painful osteoarthritis of the joint treated by debridement as an interim procedure. Four of these patients have since undergone joint replacement surgery for the same. One patient had infected gouty arthritis needing synovectomy and debridement of his MTP joint followed by mini-external fixator application for wound healing. One patient had bilateral meniscoid impingement lesions, needing excision.
Technique : Under general anaesthesia and tourniquet control, patient lying supine, gentle traction was applied on the great toe. The joint was insufflated with 5 mls of normal saline with a 23-gauge needle inserted just medial to the extensor hallucis longus (EHL) tendon [Figure - 1]. A second needle is inserted lateral to the EHL and when a free flow of fluid is established, small stab incisions are made over the joint medial and lateral to the EHL tendon. A small forceps spreads the soft tissue and the capsule is identified. This helps in preventing injury to the cutaneous branch of the superficial peroneal nerve at the dorsomedial portal. An accessory medial portal may be necessary sometimes for accessing lesions on the plantar aspect of the joint as well as for accessing the two sesamoids. Care was taken to avoid injury to the dorsal synovial fold when introducing the 2.7mm cannula through the medial portal. This thin synovial fold was found intracapsularly, attaching proximal and posterior to the dorsal articular cartilage of the first MT head.
A 2.3-mm arthroscope with a 30° obliquity was used to visualize the joint through the dorsal lateral portal. The most useful instruments for inspection of the joint is a 2mm probe, appropriate diameter of cutting instruments and graspers, and a 2 mm small joint power tool. The assistant provides traction to the toe if required.
Intra-articular examination includes: the lateral gutter, the lateral corner of the MT head, the central portion of the MT head, the medial corner of the MT head, the plantar half of the MT head, the medial gutter, the medial portion of the proximal phalanx, the lateral portion of the proximal phalanx, the medial and the lateral sesamoids. The sesamoids can be seen through the dorso-medial or straight medial portal. It is necessary to excise any adhesions or osteophytes in the sesamoid metatarsal joint as these may be responsible for the presenting symptoms. Dorsal Osteophytes may be removed arthroscopically with the small joint shaver only if they are small in size.
The wounds were closed with 3-0 nylon and a bulky dressing was applied. We use appropriate antibiotic and anticoagulant prophylaxis. Immediate range of motion exersises is encouraged. The sutures were removed at ten days and normal weight bearing and shoe wearing is then allowed when swelling is reduced.
| Results|| |
The average tourniquet time is 30 minutes. All patients had an uneventful post-operative recovery period. Analgesia was required for only twenty four hours. Pathologies seen and the procedure used are described in [Table - 1].
The mean AOFAS (Hallux MTP-IP) scores at two years following the procedure were 97 (87 - - 100).
| Discussion|| |
Following Watanabe's  first description of MTP joint arthroscopy, many authors have performed and published successful outcomes ,,,, . Initially arthroscopy was used for diagnostic purposes. Gradually as skills in this advanced technique improved, arthroscopic procedures were introduced in the armamentarium. Arthroscopic debridement of osteochondritis dissecans was one of the early procedures carried out  . The advantages of arthroscopic treatment include less soft tissue dissection avoiding a large capsulotomy, decreased post-operative pain, lesser post operative stiffness, with an improved outcome in selected group of symptomatic first MTP joint pathology.  Arthroscopic synovectomy has given long-term pain relief in patients having early OA with synovitis. 
It is vital to appreciate the internal correlates of the 1st MTP joint as also to understand the pathology that is responsible for the symptoms. This is especially important in using the arthroscope for the treatment of conditions affecting the sesamoid-metatarsal joint owing to its complex geometry  , difficulty in access and problems in maneuvering instrumentation in this confined space. The synovium and capsule enclose the ball and socket articulation between the proximal phalanx and the metatarsal head. The ligaments and the musculo-tendinous structures provide the external support. The dorsum of the first MTP joint is divided into two halves by the extensor hallucis longus (EHL) tendon. Each half has a separate nerve supply (medial half - - branches of superficial peroneal nerve and lateral half - branches of deep peroneal nerve). The most commonly used portals for introducing the arthroscope are dorsal medial and lateral portals, which are on either side of the EHL., A blunt dissection with a hemostat is used to enter the joint. This avoids injury to these superficial nerve branches. One must direct the tip of the trocar and cannula away from the midline when introducing the trocar. One must avoid a thin rim of dorsal synovial fold under the joint capsule, which is located more near the midline. Injury to this structure leads to a contracture inside the joint and may lead to stiffness of the MTP joint  . To avoid scuffing the articular surface with the trocar, the joint is distracted by a constant traction applied by the assistant. The Chinese finger traps make it difficult to visualize the sesamoids through the medial portal as the plantar capsule is very tight. This is best visualized by gentle traction in a plantar flexed position. In uniaxial traction in the neutral position, the stretched capsule also pulls tightly against the dorsal osteophytes and making arthroscopic cheilectomy difficult. The sesamoid compartment is generally regarded as inaccessible, but with careful maneuvers it is possible to visualize the medial and lateral sesamoid. If the lateral sesamoid is too displaced laterally it is difficult to visualize. The dorso-medial portal is ideal for visualizing the medial sesamoid. But sometimes due to osteophytes it is increasingly difficult to access the zone unless the osteophytes are removed.
We have performed diagnostic arthroscopies in the hallux rigidus group with a view to debridement and cheilectomy provided the dorsal osteophyte is not bigger than 5 to 7 mm. Larger osteophytes are better dealt with using a mini arthrotomy as the capsular thinning would make the possibility of cutaneous nerve injury with the shaver equipment. In our series, debridement of the joint and removal of osteophytes rendered the patient painfree for 24 months (mean) before requiring definitive treatment. We agree with the belief of Davies and Saxby that there is a group of young to middle aged patients in the middle of the spectrum of primary osteoarthritis of the hallux MTP joint who are suitable for arthroscopy. These patients have persistent pain and swelling of the first MTP joint who have failed to respond to conservative treatment and are 'too good' a candidate for arthrodesis or arthroplasty.  In addition, they do not show signs of advanced arthritis in conventional radiographs.
In our series, the patient with bilateral arthrofibrosis had a 'meniscoid lesion' on the dorsal aspect of the MT head, which was removed arthroscopically with a cutting device, resulting in complete pain relief.
To these indications we add fractures of the proximal phalanx or the MT head with intra-articular extension. The joint fracture was visualized arthroscopically and the fracture reduction was effected by manipulation and "joysticking" with a K wire. This technique of visualizing the joint surface in fractures avoids the need for a large arthrotomy adding to the problems of post traumatic arthrosis and stiffness.
Arthrodesis of the great toe MTP joint in carefully selected patients is possible through the arthroscope but fraught with danger.  We had to convert to open arthrodesis in a patient with hallux rigidus earlier in our series. The equipment is delicate and damage to the scope and/or instruments being a very real possibility.
Complications of arthroscopy of this small joint is categorized as systemic, preoperative and procedure related. The procedure related complications range from nerve injury due to poorly placed portals, iatrogenic articular cartilage injury, instrument breakage, inadequate fluid management, compartment ischemia, infections, effusion after surgery, CRPS I and persistent pain and stiffness.  We had two patients with superficial sensory loss over the medial aspect of the great toe, which recovered within two months of the arthroscopy. One patient had persistent stiffness in the left MTP joint following debridement and excision of chondral lesion.
To avoid the complications, a careful preoperative assessment of the patient's general condition along with assessment of the skin, nerves and vascular status is performed. A thorough knowledge of the anatomy and prior practice on cadaveric joints would help to have an orientation. The distraction by assistant should be adequate which avoids superficial scrapes, nicks and scuffing of the articular surface. Proper care is necessary to prevent catastrophic instrument failure while in the joint. Metallic debris from the shaver could remain in the joint, which needs to be removed by suction and irrigation. Magnetic retriever should be available if required. Portal placement should be performed meticulously. Peri-operative antibiotics are not used routinely. This may jeopardize function by causing pain and stiffness and result in difficult post-op recovery. A limited operating time and tourniquet use of maximum one hour may reduce the rate of complications. A short post-operative immobilization with heel weight bearing for the first two weeks gives adequate rest for the joint to recover.
Good to excellent results have been reported between 80 --100%.,,,,, In our series, there was both subjective and objective improvement in the symptomatic great toe MTP joint especially in younger patients with hallux rigidus. These patients seem to do well until they have their definitive treatment at a later date. Arthroscopic debridement or synovectomy or cheilectomy improves the quality of life and patients are able to wear their normal shoes comfortably. It could be put to good use for intra-articular fractures, which needs accurate reduction in young patients for preventing post traumatic arthrosis. We had good to excellent functional and painfree great toe MTP joints in all patients. Four patients then returned after a mean of 2 years for their total joint replacements.
Arthroscopic management of painful hallucial MTP joint is a specialized technique and is not for the occasional arthroscopist, which if performed for the right indications, gives a favorable outcome with minimal complications. The technique of first MTP arthroscopy once learned by an average surgeon may be used to beneficial effect as day case procedures for the indications mentioned.
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U K Debnath
23, Barons Court Road, Penylan, Cardiff, CF23 9DF, UK
[Figure - 1], [Figure - 2], [Figure - 3]
[Table - 1]