How To Select The Right Procedure For Hallux Limitus

Author(s): 
By Harold Schoenhaus, DPM

When it comes to hallux limitus, there are several circumstances in which one may see this decreased range of motion of the first metatarsophalangeal joint. You may note a limited range in the direction of dorsiflexion, plantarflexion or both. Depending upon the etiology, you may see the restriction during nonweightbearing, static stance or during the propulsive phase of gait. The etiology may be secondary to direct macrotrauma to the great toe joint, metabolic conditions such as gouty arthritis or, most commonly, first ray hypermobility associated with abnormal pronation. Hypermobility of the first ray causes an elevation in propulsion that decreases the ability of the hallux to dorsiflex on the first metatarsal. This prevents the necessary 65 degrees of dorsiflexion in propulsion and increases compressive forces across the joint. The compressive forces, which are repetitive and microtraumatic, lead to inflammatory, degenerative and proliferative changes. These forces affect the bone cartilage and synovium, causing objective and subjective findings. As the process continues, one will see a thinning of cartilage, bone proliferation, hypertrophic changes to the synovium and functional adaptation of the joint. You will usually see exostosis formation dorsally but it may also occur medially and laterally. While hallux limitus is most commonly seen as a sagittal plane deformity, you may also see it with hallux abducto valgus secondary to hyperpronation and first ray hypermobility. Understanding the four stages of hallux limitus is vital because treatment is often predicated on these stages. Dealing With Joint Inflammation And Jammed Motion In Dorsiflexion Stage I. Joint inflammation and jamming of dorsiflexion motion in propulsion are the hallmarks of Stage I. These patients will have a normal, nonweightbearing range of motion and you will not note any X-ray changes. If the symptoms are associated with direct trauma, prescribing antiinflammatory medication, corticosteroid injections and physical therapy is usually adequate. If the etiology is metabolic in nature, as seen with gout, antiinflammatory medication, injections and uricosuric or xanthine oxidase inhibitors are indicated. When hyperpronation is the cause, add orthotics to the treatment plan. A Guide To Diagnostic Signs And Treatments For Stage II Stage II. In this stage, patients begin to show objective clinical signs in addition to the inflammation of Stage I. You will note a dorsal proliferative response that is palpable and evident on X-ray as well. The patient will have a limited range of motion in dorsiflexion due to exostosis formation and one may see some narrowing of the joint space on X-ray. These objective findings are early changes of degenerative joint disease. Hypertrophy of the dorsal capsule develops as it grows over the developing exostosis (dorsal spurring). The contour of the articular surfaces is minimally affected and will allow for relatively normal curvilinear motion. After exhausting the aforementioned conservative approaches to alleviate discomfort, one can consider surgical intervention. Be sure to explain the goals of surgery clearly to the patient. Reducing pain, removing the offending bone and improving range of motion are the primary goals. A cheilectomy is the procedure of choice for removing the offending bone. One should begin with a dorsal S-shaped incision in order to avoid postoperative scar contraction. Drilling minor cartilaginous defects through subchondral bone helps promote the proliferation of fibrocartilage. If adjacent soft tissue structures are tight, you may apply a mini fixator for joint distraction and use it for four to six weeks. You can employ manual range of motion in the direction of dorsiflexion and plantarflexion, even with the fixation in place, while still maintaining a distraction force. Early range of motion is essential for maintaining healthy cartilage and allowing for the proliferation of fibrocartilage. Postoperative orthotic control is essential if the underlying cause is first ray hypermobility secondary to pronation. Key Diagnostic Indicators Of Stage III Hallux Limitus Stage III. This is an advanced Stage II with significant objective findings. One will see changes in the contour of the joint that are secondary to compressive forces in propulsion. There will be a flattening of the metatarsal head in the sagittal and transverse plane that you can see clinically and radiographically as a widened joint dorsally and laterally. These patients will often have proliferative disease with a “Valente” spur. X-rays will also show narrowing of the joint space secondary to thinning of articular cartilage. On occasion, a lateral X-ray may show increased joint space on the more dorsal aspect of the metatarsal head that is caused by a dorsal concentration of compressive forces. You will see a mushrooming of the metatarsal head. When assessing these patients, you will note a significantly diminished range of motion and they will often have crepitation. The restriction of motion is greatest in dorsiflexion, but will also be present in plantarflexion. The patients will experience pain with passive range of motion and you will notice soft tissue contractures plantarly. These structures include the plantar aponeurosis (sesamoid extension of the conjoined tendons of the flexor hallucis brevis, abductor hallucis and adductor hallucis.) The flexion hallucis longus will also be contracted. One will see initial signs of degenerative change at the base of the proximal phalanx with thinning of articular cartilage and an apparent deepening of the cup secondary to the thinning cartilage. You will note some peripheral proliferative changes as well. An Overview Of Surgical Goals For Stage III Hallux Limitus At this stage, emphasizing decompression of the joint is important for relaxing the plantar soft tissues. Also be aware that first ray hypermobility may have resulted in a functional adaptive change with metatarsus primus elevatus. This is a structural deformity and will ultimately influence the postoperative range of motion in the sagittal plane. Options for surgical intervention include decompression or resectional arthroplasties with or without joint replacement. One should also address elevatus of the first ray, which you can correct with plantarflexory osteotomies or via an aggressive angular resection of the metatarsal head (such as a hemi-Valenti procedure or modified Stone procedure). Surgeons can angulate the hemi-Valenti procedure from the mid-portion of the first metatarsal head or from the inferior portion of the metatarsal head angulated dorsally and proximally. This allows for curvilinear motion of the base of the proximal phalanx. Once you have completed this step, there should not be any articular cartilage left from the resected head. If the cartilage on the metatarsal head is relatively normal and covering the majority of the metatarsal head, you can perform a Waterman osteotomy, which will facilitate minimal decompression and still allow for angulation of the head for range of motion. Pearls For Performing The Keller Without Using An Implant Decompression of the joint is essential for improving range of motion and diminishing pain. As far as preferred procedures go, I prefer to perform a Keller resection of the base with implantation. When opting for a Keller without an endoprosthesis, you will resect less bone than you would with an implant and employ imbricated capsular tissue as a spacer between the remodeled head and remaining base of the proximal phalanx. Do not remove the plantar intrinsics from the proximal phalanx as their insertion extends onto the shaft of the proximal phalanx. During this procedure, one may use an external fixator adjunctively to maintain a space for proper imbrication of the capsular tissue. You can also use the device postoperatively to maintain correct alignment and distraction, and allow for early passive range of motion. The device is usually removed in four to six weeks. If you are treating patients who are concerned about implant material or who have an allergy to the material, you should consider the Keller. Also, patients who do not wish to risk the need for implant replacement in the future are Keller candidates. Keep in mind that some shortening of the great toe is expected and necessary to decompress the joint and allow for increased dorsiflexion. Key Considerations For Using An Endoprosthesis I prefer to use an endoprosthesis to replace the resected base of the proximal phalanx. This prevents the need to rely on an imbricated capsule to act as a spacer. Keep in mind that using an imbricated capsule can breakdown or lead to scarring. It also prevents the resected base from leaving denuded bone to articulate against adjacent soft tissue or bone with subsequent irritation and scarring. When considering an endoprosthesis, make sure the patient has adequate bone stock that will accept the stem of the implant and provide a stable environment to counteract rotation or slippage. The thickness of the implant should be no greater than 5 mm as this allows for appropriate bone resection and replacement, and facilitates decompression without excessive shortening of the hallux. Employing a titanium implant allows for more aggressive remodeling of the head and it will not break down or create reactive shards as one would see with silicone implants. If the patient’s bone stock is inadequate or the remaining proximal phalanx is fatty or hollow, one can use injectable graft to fill the void. Doing so helps secure the stem of the implant. The product I use is minimally invasive injectable graft. When it comes to selecting a hemi-implant, there are two low profile implants available that I have used. One such implant also has sizes with altered shapes to account for abnormalities in the proximal articular set angle. These implants are spacers that will allow for improved motion without reaction. Pertinent Points For Treating Advanced Degenerative Joint Disease Stage IV. In Stage IV hallux limitus/rigidus, there is severely advanced degenerative joint disease with complete loss of articular cartilage on both sides of the joint as well as a loss of joint space. The joint is flattened and wide in all planes with severe limitation of motion in all planes and directions. In my experience, one can choose from three procedures: the aforementioned Keller; using a hemi-implant with significant alteration of the contour of the metatarsal head; or fusion. I have also used a double-stemmed implant on occasion. There are options for fusion. One approach is performing minimal resection of bone using resurfacing instruments such as a conical reamer. This allows for minimal resection and an end to end fusion with fixation. Another alternative includes resecting the diseased parts with an interpositional iliac crest bone graft. One would employ bone plates or external fixation for stabilization. When performing a fusion, you can use orthobiologic products such as Allomatrix and Symphony, an autologous platelet gel, to fill bony defects. One should be sure to place the hallux in approximately 10 to 15 degrees of dorsiflexion. Doing so allows the patient to wear a shoe with a small heel, which can assist in propulsion. Autograft is my graft of choice and is usually harvested by an orthopedic surgeon. Prolonged immobilization is necessary with a fusion. Final Thoughts While I have found these recommended procedures for hallux limitus/rigidus the most successful, one’s surgical judgment often is the deciding factor when choosing the most appropriate treatment. Dr. Schoenhaus is the Chief of Foot and Ankle Surgery at the Graduate Hospital in Philadelphia. He is a Past President and Fellow of the American College of Foot and Ankle Surgeons. Dr. Schoenhaus is board-certified by the American Board of Podiatric Surgery and the American Board of Podiatric Orthopaedics and Primary Podiatric Medicine. CE Exam #115 Choose the single best response to each question listed below. 1. Stage I hallux limitus is marked by a) a dorsal proliferative response that is palpable and seen on X-ray as well b) a flattening of the metatarsal head in the sagittal and transverse planes c) joint inflammation and jamming of dorsiflexion motion in propulsion d) early changes of degenerative joint disease 2. The primary goals of surgery for Stage II hallux limitus do not include: a) improving the range of motion b) decompression of the joint c) removing the offending bone d) reducing pain 3. Hallux limitus is most commonly caused by … a) direct macrotrauma to the great toe joint b) metabolic conditions such as gouty arthritis c) first ray hypermobility associated with abnormal pronation d) none of the above 4. If the symptoms of Stage I hallux limitus are associated with macrotrauma, which treatment is usually adequate? a) corticosteroid injections b) physical therapy c) antiinflammatory medication d) all of the above 5. Which of the following statements about Stage II hallux limitus is false? a) You will note a dorsal proliferative response that is palpable and evident on X-ray as well. b) The contour of the articular surfaces is significantly affected and will not allow for relatively normal curvilinear motion. c) You will see hypertrophy of the dorsal capsule develop as it grows over the developing exostosis. d) The patient will have limited range of motion in dorsiflexion due to exostosis. 6. Which of the following statements is incorrect about performing a Keller without an endoprosthesis? a) You will remove the plantar intrinsics from the proximal phalanx. b) You will resect less bone than you would with an implant. c) You can use imbricated capsular tissue as a spacer between the remodeled head and remaining base of the proximal phalanx. d) None of the above. 7. In regard to performing the Keller without an endoprosthesis, you can use an external fixator … a) adjunctively to maintain a space for proper imbrication of the capsular tissue b) postoperatively to maintain correct alignment and distraction c) postoperatively for four to six weeks d) all of the above 8. In regard to using an endoprosthesis to replace the resected base of the proximal phalanx, which of the following statements is true? a) The thickness of the implant should be no greater than 3 mm. b) One should ensure the patient has adequate bone stock that will provide a secure environment for the implant. c) Using a titanium implant allows for more aggressive remodeling of the head but has a higher risk of breakdown than silicone implants. d) None of the above 9. Which of the following surgical procedures can be used to treat Stage IV hallux limitus/rigidus? a) a hemi-implant with significant alteration of the contour of the metatarsal head b) fusion c) the Keller d) all of the above Instructions for Submitting Exams Fill out the postage-paid card that appears on the following page or log on to www.podiatrytoday.com and respond electronically. Within 60 days, you will be advised that you have passed or failed the exam. A score of 70 percent or above will comprise a passing grade. A certificate will be awarded to participants who successfully complete the exam. Responses will be accepted up to 12 months from the publication date.

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