Abstract

INTRODUCTION
The 22nd Annual Summer Meeting of the American Orthopaedic Foot and Ankle Society (AOFAS) was held July 14–16, 2006, at the Hilton Torrey Pines Hotel in La Jolla, California. There were 453 registrants in attendance, including 91 individuals from 23 countries outside the United States.
SCIENTIFIC SESSIONS
Reconstruction
Charcot foot: In 20 patients with Charcot midfoot arthropathy with collapse of the longitudinal arch, surgical correction included osteotomy, bone resection, and intramedullary screw fixation.
65
Bony union was achieved in 15 (75%) patients at an average of 6 months after surgery, and all patients resumed functional ambulatory status within 9.5 months; two (10%) patients developed recurrent plantar ulcer.
65
Foot drop: In 39 patients with neuropathic foot drop, the bridle procedure (posterior tibial tendon transfer through the interosseous membrane to the dorsum of the foot) was done.
39
Evaluation at an average of 43 months after surgery showed that 37 (95%) patients were able to ambulate without a brace, and ankle range of motion was decreased in all patients.
39
Talar osteochondral defect: Five surgical approaches were done on eight cadaver ankles to determine access to the posterolateral talar dome for osteochondral plug harvesting for treatment of talar osteochondral defects.
50
Posterolateral exposure of the talar dome was greatest with fibular osteotomy and release of the anterior talofibular and calcaneofibular ligaments.
50
Osteochondral ankle allograft: In 29 ankles (29 patients; average age, 41 years) with arthritis, treatment included tibial and talar osteoarticular allograft replacement.
28
Evaluation at an average of 18 months after surgery showed that failure occurred in 18 (62%) ankles, and failure was significantly associated with higher body mass index, younger age, and larger preoperative coronal plane deformity.
28
Computer-Assisted Surgery
Arthrodesis: In 10 patients who were evaluated at an average of 14 months after computer-assisted arthrodesis of the ankle, subtalar, or Lisfranc joints, all planned angles and translations were achieved.
48
There was no difference between corrected angles and translations at surgery with those at followup evaluation.
48
Total ankle arthroplasty: Experimental preparation of the tibia for total ankle arthroplasty was done in seven matched pairs of cadaver lower extremities to compare conventional external tibial alignment guides against a computer-navigated preparation system.
15
There was no significant difference between the two methods in tibial preparation achieved.
15
Talar osteochondral defect: A computer-assisted system with three-dimensional imaging was used for retrograde drilling of stage I and II talar osteochondral defects.
17
In nine patients who were evaluated at an average of 18 months after surgery, postoperative imaging confirmed accurate drilling position and average score on a visual analog scale was 92 points.
17
Total Ankle Arthroplasty
Total ankle prosthesis: A new total ankle prosthesis was designed (Topez Orthopedics, Boulder, Colorado) with an intramedullary guidance system, a tibial stem, and a talocalcaneal stem.
47
Gait: A gait laboratory study compared gait parameters and functional tests in four groups of subjects (12 subjects per group): ankle arthrodesis (postoperative), total ankle arthroplasty (6 and 12 months after surgery), and normal control subjects.
43
Subjects in the arthrodesis group had greater walking velocity and step length than arthroplasty subjects; arthroplasty subjects had a more symmetrical gait than arthrodesis subjects.
43
Muscle rehabilitation: In 15 patients who had total ankle replacement for osteoarthritis, evaluation at 1 year after surgery showed significant improvement compared with preoperative values of mean dorsiflexion torque (preoperative, 16 Nm; postoperative, 23 Nm) and plantarflexion torque (preoperative, 16 Nm; postoperative, 22 Nm).
61
Electromyography of leg muscles of the affected side compared with the healthy, contralateral side at 1 year after surgery showed that mean EMG frequency of atrophic muscles remained low and unchanged but mean EMG intensity improved.
61
This study received the J. Leonard Goldner, M.D. Award. Talar component: A custom-made, stemmed talar component was used in 30 patients who had revision total ankle arthroplasty (26 patients) or primary total ankle arthroplasty (4 patients with talar osteonecrosis or large talar cysts).
3
Evaluation at a mean of 16 months after surgery showed mean improvement of AOFAS Ankle-Hindfoot score of 18 points; complications included residual pain in two patients, stem fracture in one patient, chronic infection in one patient, and below-knee amputation in one patient.
3
Sports
Jones fracture: A simulated Jones fracture was made in 21 pairs of cadaver fifth metatarsals, fixed with two types of screws (partially-threaded lag screw or fully-threaded tapered screw), and cyclically loaded.
41
Comparison of the failure mechanisms of the two screw constructs showed that the partially-threaded lag screw more frequently fractured the metatarsal distal to the fracture site, and the fully-threaded tapered screw more frequently pulled out of the proximal fragment.
41
Jones fracture: In 20 athletes with a Jones fracture treated with 5.5-mm diameter cannulated screw fixation, evaluation at an average of 23 months showed that all fractures healed clinically, and all patients returned to pre-injury sports participation.
44
There was no difference in clinical and radiographic union rates between this group and another cohort treated with 4.5-mm diameter cannulated screw fixation.
44
Lisfranc joints: In 10 cadaver specimens evaluated with weightbearing, abduction, and adduction stress radiographs, sectioning the Lisfranc (interosseous cuneiform1-metatarsal2) ligament alone did not produce instability (instability defined as radiographic displacement ≥ 2 mm).
27
Subsequent section of the plantar cuneiform1-metatarsal2 ligament in five specimens produced cuneiform1-metatarsal2 and cuneiform2-meta-tarsal2 instability to abduction stress in all five specimens; section of the cuneiform1-cuneiform2 ligament in the other five specimens produced cuneiform1-cuneiform2 instability to adduction stress in four of five specimens.
27
Nerve Disorders
Deep peroneal nerve: Dissection of 22 cadaver feet showed that the lateral branch of the deep peroneal nerve did not end as a muscular branch to the extensor digitorum brevis, but arborized into five main branches.
53
Two areas of compression of the lateral branch of the deep peroneal nerve were identified: the fascial border of the extensor digitorum brevis muscle and the talar head.
53
Chronic pain: In 35 patients with chronic dystrophic foot and ankle pain, treatment included a modified total contact cast.
63
Pain and dystrophic symptoms were improved after an average of 6 weeks of casting in 26 (74%) patients; 9 (26%) patients had minimal or no improvement of symptoms.
63
Tarsal tunnel syndrome: Five patients with severe recurrent tarsal tunnel syndrome had early satisfactory results after revision tarsal tunnel release and nerve wrapping using highly processed bovine Achilles tendon.
33
Interdigital neuroma: A survey of 119 patients at an average of 67 months after excision of an interdigital neuroma showed that results were good or excellent in 59 (50%) patients, fair in 12 (10%) patients, and poor in 48 (40%) patients.
67
Sports
Ankle instability: In 32 patients who had arthroscopic thermal-assisted capsular modification for treatment of functional ankle instability, evaluation at an average of 29 months after surgery showed that average AOFAS Ankle-Hindfoot Score was improved (preoperative, 67 points; postoperative, 93 points), and 24 (75%) patients returned to their desired level of sporting activities.
31
Ankle instability: A retrospective survey of 73 patients at an average of 64 months after a Brostrøm-Gould procedure for treatment of chronic lateral ankle instability showed that 16% of patients had residual functional instability.
7
The residual instability was not reflected in the average AOFAS Ankle-Hindfoot Score (95 points), but the mean physical component score of the Short Form 36 (SF-36) (84%) reflected the presence of functional instability.
7
Medial malleolar fracture: A simulated vertical shear fracture of the medial malleolus was made in polyurethane tibial models, fixed with varied plate and screw constructs, and loaded to failure.
14
Use of an antiglide, one-third tubular plate was beneficial.
14
Hallux Valgus
Hallux valgus: A survey of academic orthopaedic foot and ankle surgeons showed that mild hallux valgus in a hypothetical 60-year-old woman would be treated with a distal chevron osteotomy by 90 (87%) of 103 surgeons.
42
For severe hallux valgus in a hypothetical 50-year-old woman, surgical procedures selected were varied and included metatarsal osteotomy, first metatarsophalangeal joint arthrodesis, and Lapidus procedure.
42
Proximal crescentic osteotomy: In 122 feet (103 patients) with hallux valgus deformity treated with proximal crescentic osteotomy and distal soft-tissue repair, evaluation at a mean of 26 months after surgery showed improvement of mean hallux valgus angle (preoperative, 30 degrees; postoperative, 10 degrees), 1–2 intermetatarsal angle (preoperative, 15 degrees; postoperative, 5 degrees), and AOFAS score (preoperative, 57 points; postoperative, 91 points).
12
There was no relationship between preoperative first ray mobility and preoperative plantar gapping of the first metatarsocuneiform joint.
12
Chevron osteotomy: In 31 feet (28 patients) with moderate to severe hallux valgus deformity, treatment consisted of chevron osteotomy with lateral soft-tissue release.
10
Evaluation of 17 patients with a visual analogue scale at a minimum of 2 years after surgery showed that average overall satisfaction was 1.8 points out of 10 points (10 points = completely unsatisfactory), and there were no cases of hallux varus or osteonecrosis of the first metatarsal head.
10
Distal metatarsal osteotomy: In 1000 feet with hallux valgus treated with a minimally invasive distal metatarsal osteotomy, evaluation at an average of 37 months after surgery showed improvement of average hallux valgus angle (preoperative, 32 degrees; postoperative, 18 degrees), 1–2 intermetatarsal angle (preoperative, 14 degrees; postoperative, 6 degrees), and AOFAS score (preoperative, 48 points; postoperative, 89 points).
18
Flatfoot
Posterior tibial muscle: In seven cadaver specimens, isolated forefoot abduction or hindfoot eversion resulted in lengthening of the posterior tibial muscle, and isolated forefoot adduction or hindfoot inversion resulted in shortening of the posterior tibial muscle.
16
Posterior tibial tendon: In seven cadaver specimens, posterior tibial tendon excursion and work of friction were determined before and after creation of a flatfoot deformity.
4
For both the intact and flatfoot conditions, average maximal posterior tibial tendon excursion was greater in the coronal and transverse planes than in the sagittal plane; average tendon excursion and work of friction in the coronal and transverse planes were significantly greater in the flatfoot than in the intact condition.
4
Flatfoot reconstruction: In 42 patients with flexible adult acquired flatfoot deformity, treatment included lateral column lengthening in 25 (60%) patients and medial calcaneal osteotomy in 17 (40%) patients.
60
Initial average correction of the talonavicular coverage angle was similar with the two procedures (lateral column lengthening, 16 degrees; medial calcaneal osteotomy, 14 degrees), but at an average of 2 to 3 years after surgery, average loss of correction was greater with medial calcaneal osteotomy (lateral column lengthening, 0.7 degree; medial calcaneal ostetomy, 7 degrees).
60
Soft Tissue
Anterior tibial tendon transfer: In 10 cadaver specimens, plantar foot pressures were measured after both split or whole anterior tibial tendon transfers in simulated normal and spastic stance conditions.
24
The whole tendon transfer to the lateral cuneiform resulted in more unloading of the lateral forefoot than the split transfer to the cuboid for both normal and spastic stance conditions.
24
Plantar fascia: In 12 cadaver specimens, a strain gauge was placed along the medial band of the plantar fascia and strain was measured in different foot and ankle positions.
13
The combination of ankle and metatarsophalangeal joint dorsiflexion increased plantar fascia strain by 11% over neutral position, and strain was further increased to 14% over neutral position by adding midfoot abduction.
13
Achilles tendon: Twenty-eight feet (26 patients; average age, 66 years) with calcific insertional Achilles tendinosis were treated with complete detachment of the Achilles insertion, debridement of tendinosis, calcaneal ostectomy, and repair of the Achilles tendon insertion to the calcaneus with suture anchors; postoperative treatment included immediate weightbearing in a cast brace and early range of motion exercises.
37
Evaluation at an average of 25 months after surgery showed that 92% of patients rated the outcome as good or excellent and returned to their desired activity level.
37
Plantar fasciitis: Thirty feet (22 patients) with chronic plantar fasciitis were treated with extracorporeal shock wave treatment.
29
Evaluation (dolorimeter, startup pain, and walking distance) at 12 weeks after treatment showed that 20 (67%) feet were improved, and evaluation at 1 year after treatment showed that 27 (90%) feet were improved.
29
Magnetic resonance imaging before and 1 year after the procedure showed no change in plantar fascia thickness.
29
Hallux Rigidus
Hallux rigidus: In 25 patients who had cheilectomy for hallux rigidus, measurement of maximal passive first metatarsophalangeal joint dorsiflexion with three methods (clinical estimate, goniometry, and fluoroscopy) showed differences between all three methods.
36
Cheilectomy: In 15 patients who had cheilectomy for hallux rigidus and who were evaluated at an average of 1.7 years after surgery, three-dimensional kinematic analysis showed improvement in average first metatarsophalangeal joint dorsiflexion, both active (preoperative, 12 degrees; postoperative, 24 degrees; p = 0.009) and in gait (preoperative, 18 degrees; postoperative, 32 degrees; p = 0.004).
30
Plantar pressure studies showed no significant differences between preoperative and postoperative pressures.
30
This study received the Roger Mann Award. Hemiarthroplasty: In 15 feet (14 patients) that had first metatarsophalangeal implant hemiarthroplasty for hallux rigidus, evaluation at an average of 48 months after surgery showed that patients were very satisfied for seven (47%) feet, satisfied with reservations for five (33%) feet, and dissatisfied for three (20%) feet.
5
Average total first metatarsophalangeal joint motion increased by 10 degrees from before surgery to followup evaluation.
5
Interposition arthroplasty: Eleven feet (11 patients) with grade III hallux rigidus were treated with capsular interposition arthroplasty.
45
Evaluation at an average of 22 months after surgery showed improvement in the average AOFAS Hallux Metatarsophalangeal-Interphalangeal Score (preoperative, 51 points; postoperative, 80 points), and nine (82%) patients were satisfied with the result.
45
Arthrodesis or hemiarthroplasty: In 48 feet (46 patients) with hallux rigidus, treatment consisted of first metatarsophalangeal joint arthrodesis in 27 (56%) feet and metallic implant hemiarthroplasty in 21 (44%) feet.
2
Evaluation at an average of 30 months after arthrodesis and 79 months after hemiarthroplasty showed that none of the arthrodesis cases required revision, but five (24%) implants required further surgery because of failure of the hemiarthroplasty; average followup AOFAS Hallux Score and visual analog score were significantly better for arthrodesis than hemiarthroplasty.
2
Hemiarthroplasty: In 41 feet (39 patients) with hallux rigidus that were treated with metallic implant hemiarthroplasty, seven (17%) implants were revised at an average of 29 months after implantation.
26
Evaluation of 30 patients at an average of 34 months after surgery showed that average AOFAS Hallux Score was 74 points, average Short Form 36 physical component score was 78 points, and 67% of patients were satisfied.
26
Total Ankle Arthroplasty
Meta-analysis: A meta-analysis was done to compare results of ankle arthrodesis (39 studies, 1262 patients) with total ankle replacement (17 studies, 1230 patients).
22
The two procedures were similar in mean AOFAS Ankle-Hindfoot Score (arthrodesis, 76 points; arthroplasty, 79 points) and outcome rating (percent excellent results: arthrodesis, 31%; arthroplasty, 30%).
22
Total ankle arthroplasty: The Scandinavian Total Ankle Replacement prosthesis was used in 84 ankles (80 patients).
25
Evaluation at 6 to 8 years after surgery showed that 80 (95%) prostheses remained implanted, seven (9%) patients had a complication within the first 3 months after surgery, and 15 (19%) patients had a major reoperation during the postoperative or followup period.
25
Total ankle arthroplasty: The SALTO total ankle prosthesis was used in 101 ankles (97 patients), and 10% of cases had a perioperative malleolar fracture.
6
Evaluation at a minimum of 5 years after surgery showed that four (4%) prostheses had been removed and repeat surgery had been done in five (5%) other ankles; mean AOFAS Ankle-Hindfoot Score was improved (preoperative, 28 points; follow-up, 81 points).
6
Hindfoot Fusions
Ankle fusion: In 22 patients who had revision tibiotalar arthrodesis with ring external fixation (average duration of external fixation, 15 weeks), evaluation at an average of 51 months showed that union was achieved in 19 (86%) patients.
66
Complications included symptomatic malunion in three patients, deep infection in two patients, and wound dehiscence in two patients.
66
Tibiotalocalcaneal arthrodesis: Tibiotalocalcaneal arthrodesis was done in 18 feet and ankles (17 patients) with a proximal humeral locking plate from a lateral transfibular approach.
1
Fusion was achieved in 17 (94%) feet and ankles in 16 patients at an average of 21 weeks, and evaluation at 21 months after surgery showed that these 16 patients had no pain.
1
Ankle and subtalar fusion: In 60 patients who had arthroscopic ankle arthrodesis, 53 (88%) patients had union at an average of 11 weeks.
58
In 25 patients who had arthroscopic subtalar arthrodesis, all 25 (100%) patients had union at an average of 8 weeks.
58
Reconstruction
First metatarsophalangeal joint arthrodesis: In 53 feet (49 patients) that had been treated with first metatarsophalangeal joint arthrodesis with dome-shaped reamers and a low-profile, dorsal, titanium plate, union was achieved in 49 (92%) feet at an average of 12 weeks after surgery.
20
Evaluation at a minimum of 1 year after surgery showed that the clinical result was excellent in 35 (66%) feet, good in 16 (30%) feet, and fair in two (4%) feet.
20
Allograft: Twelve hindfoot arthrodesis procedures (seven tibiotalocalcaneal and five ankle arthrodesis procedures) were done in 12 patients using structural, fresh frozen, femoral head allografts for extensive bone loss.
46
Union was noted in 9 (75%) feet and ankles at an average of 4months.
46
XIV. Posterior Tibial Tendon
Tenosynovitis: In 17 ankles (15 patients) with stage 1 posterior tibial tendinopathy, local anesthetic tendon sheath injection with fluoroscopic confirmation resulted in complete relief of symptoms in 17 (100%) ankles.
11
Magnetic resonance imaging showed increased fluid signal in the posterior tibial tendon sheath in 15 (88%) ankles; the two ankles that had negative magnetic resonance scans had pain relief after local anesthetic injection and tenosynovectomy.
11
Acquired flatfoot: In 27 feet (25 patients) with stage IV adult acquired flatfoot (peritalar subluxation, ankle arthritis, and valgus tibiotalar joint), treatment consisted of either tibiotalar arthrodesis and medial column stabilization (12 feet); ankle arthroplasty and medial column stabilization (eight feet); ankle arthroplasty and triple arthrodesis (six feet); and pantalar arthrodesis (one foot).
23
Evaluation at an average of 2 years after surgery showed that all radiographic parameters improved with each treatment approach.
23
Subtalar arthroereisis: Posterior tibial tendon dysfunction was treated with subtalar arthroereisis with a subtalar implant in addition to tendon transfer, calcaneal osteotomy, and/or heel cord lengthening in 27 feet (27 patients).
62
There was no radiographic evidence of progressive deformity at 1 year after surgery.
62
Ten (37%) implants were removed at an average of 8 months after surgery because of sinus tarsi pain (nine feet) and residual supination (one foot).
62
Foot and Ankle
Ankle fracture: In patients older than 70 years (mean age, 76 years), ankle fractures were treated with open reduction and internal fixation (84 patients) or closed reduction under anesthesia and casting (27 patients).
64
Evaluation after healing showed that decreased mobility was more frequent in patients treated with closed reduction (frequency of decreased mobility: open reduction, 1%; closed reduction, 7%).
64
Forefoot amputation: In 38 legs (35 patients) with forefoot gangrene that had been treated with forefoot amputation and peripheral arterial bypass, amputation wounds healed with primary closure, delayed primary closure, or secondary healing.
55
Imaging: In 201 patients evaluated by an orthopaedic foot and ankle specialist, 31 (15%) patients presented with a magnetic resonance imaging (MRI) scan previously done and nine (4%) had MRI ordered by the specialist.
59
Of the 31 scans done prior to evaluation, 27 (87%) scans were deemed unnecessary and 15 (48%) scans had radiological interpretations immaterial to the clinical diagnosis or inconsistent with the interpretation by the specialist.
59
Tarsal coalition: Eight feet (seven adult patients; average age, 41 years) with calcaneonavicular coalition without arthritis were treated with coalition resection and extensor digitorum brevis interposition.
52
Evaluation at a mean of 57 months after surgery showed that all patients had improvement of preoperative pain, minimal or no activity limitation, and neither degenerative arthritis nor recurrence of the coalition.
52
Sciatic nerve block: Postoperative sciatic nerve block was done in 86 patients who had arthrodesis in the foot, and all patients were satisfied with postoperative pain management while the block was in effect.
56
Postoperative pain: In 40 patients who had major ankle or hindfoot surgery, postoperative pain control was compared between 20 (50%) patients who had a continuous postoperative popliteal catheter with a saphenous nerve block (0.25% bupivacaine) placed before surgery and 20 (50%) patients who had continuous surgical site infusion (0.25% bupivacaine) through a catheter placed in the surgical wound during closure.
38
Quality of pain control was significantly better in patients who had the popliteal-saphenous block, demonstrated by average visual analog score (poplitealsaphenous, 4 points; surgical site, 7 points; p < 0.0001) and total number of pain medications used (popliteal-saphenous, 3; surgical site, 10; p < 0.0001).
38
Outcomes: In 25 patients (mean age, 40 years) who had foot and ankle surgery, evaluation before and 6 months after surgery showed greater responsiveness of the Foot Function Index and AOFAS Scores compared with the Short Form 36 questionnaire.
54
CONCLUSION
The summer meeting was preceded by a special full-day seminar, “Hot Issues in Sports Injuries of the Foot and Ankle.” Highlights of the meeting included an innovative electronic poster session with 100 posters and symposia on trauma, 40 orthobiologics, 34 “Forgive and Remember,” 51 and complications of total ankle replacement. 49 Special lectures reviewed balance in life, 35 professionalism in research, 57 foot evolution, 32 the placebo value of perioperative ritual, 21 diabetic foot disease, 9 and thoughts from outgoing and incoming AOFAS presidents James W. Brodsky and Lowell H. Gill. 8,19
The summer meeting was a great success, thanks to the outstanding efforts of the AOFAS staff and generous educational grants from 68 corporate sponsors and exhibitors. The next meeting of the AOFAS will be on Specialty Day, February 17, 2007, at the meeting of the American Academy of Orthopaedic Surgeons in San Diego, California. The next summer meeting of the AOFAS will be held July 13 to 15, 2007, in Toronto, Ontario, Canada.
