Depth variations of second and third tarsometatarsal joints during dorsal compression staple fixation using two different bridge lengths: an anatomic study

Fusion of the second and third tarsometatarsal joints is utilized for various arthritic pathologies and traumatic conditions. A cadaveric study using 20 fresh-frozen transtibial specimens were used for a stimulated arthrodesis study. Half of the specimens underwent drilling via drill guide for a respective 15 mm and 20 mm dorsal bridge length staples. Each drill guide was placed equidistant from each joint at 7.5 mm for the 15 mm bridge length and 10 m for the 20 m bridge length, then drilled bicortically in parallel with the joint line. For the 15 mm bridge length on the second metatarsal, the mean depth was 22.5 mm ± 2.2, and was 26.7 mm ± 3.8 proximal on the intermediate cuneiform. For the 20 mm bridge length on the second metatarsal, the mean depth was 22.3 mm ± 2.2 and was 27.2 mm ± 2.0 proximal on the intermediate cuneiform. For the 15 mm bridge length for the third metatarsal mean depth was 21.5 mm ± 3.2, and was 24.2 mm ± 2.9 proximal on the lateral cuneiform. For the 20 mm bridge length on the third metatarsal, the mean depth was 20.3 mm ± 2.4 and was 24.6 mm ± 2.4 proximal on the lateral cuneiform. A student's two tailed homoscedastic t-Test was calculated for the 7.5 mm vs 10 mm distal and proximal distances for both second and third TMT data sets and found there was no significant differences in depth.The current study found that for both 15 mm and 20mm bridge lengths for 2nd TMT fusions a 22 mm leg length can be used appropriate and similarly for 3rd TMT fusions, a 20 m leg length appears to be appropriate fixation. Although variations will exist, advances towards indication specific fixation may allow for varied leg length for optimal boney purchase

Shortening of the first ray after first tarsometatarsal joint fusion: a cadaveric comparison between curettage versus planal resection

Potential shortening of the first ray is an important consideration when performing a first tarsometatarsal (TMTJ) fusion. However, no previous study has sought to directly quantify the resultant shortening after TMTJ fusion. The purpose of the present anatomic study was to directly assess and compare shortening of the first ray using two joint preparation techniques (curettage, planal resection) for first TMTJ fusion. Ten pairs of matched lower extremity cadaver specimens were divided into two groups. Preoperative length assessments were performed at the first TMTJ dorsally and plantarly using a digital caliper. In Group 1, joint preparation for first TMTJ fusion was performed with curettage, whereas specimens in Group 2 underwent planal resection. Post-operative length assessments were repeated. All data was analyzed using two-tailed Students t-tests. Mean shortening of the first ray following curettage was 1.1 (range, 0.3 to 2.0) mm dorsally and 1.6 (range, 0.6 to 3.7) mm plantarly; while mean shortening following planal resection was 4.5 (range, 2.7 to 7.9) mm dorsally and 4.6 (range, 2.4 to 8.9) mm plantarly. The measured differences were statistically significant (p < 0.001, p = 0.001). Both curettage and planal resection resulted in shortening of the first ray after first TMTJ fusion. Planal resection resulted in significantly more shortening, which was also more variable. Surgeons performing first TMTJ fusions may consider curettage over planal resection to mitigate the risk of painful postoperative transfer metatarsalgia

Surgical planning for staple fixation of the first tarsometatarsal joint: An anatomic study

First tarsometatarsal (TMT) arthrodesis is a common procedure utilized by foot and ankle surgeons for the management of a variety of first TMT pathology including hallux valgus and arthritis. The present study was undertaken to determine the average staple leg depth that allows for adequate purchase within the medial cuneiform and first metatarsal base at 2 different staple bridge lengths for dorsal compression across the 1st TMT joint. A cadaveric study was performed using 20 fresh-frozen below knee specimens. After TMT dissection was performed, drill holes were then created from dorsal to plantar and parallel to the first TMT joint at the distances utilized for 20 mm and 25 mm staple bridge lengths. The depths of each drill hole were measured and recorded. The mean medial cuneiform depth corresponding to a 20 mm and 25 mm staple bridge was 31.9 mm +/- 2.8 mm and 31.1 mm +/- 2.1 mm respectively (P-value = 0.38). The mean first metatarsal depth corresponding to a 20 mm and 25 mm staple bridge was 27.9 mm +/- 2.2 mm and 25.4 mm +/- 3.4 mm respectively (P-value = 0.04), showing statistical significance. Based on our anatomic data it is suggested that a 20 mm staple leg depth is consistently a safe depth when using 20×20 and 25×20 mm dorsal compression staples. However, further studies must be conducted to compare the amount of compression between the two respective staples

Beaming in Charcot Arthropathy- Intramedullary Fixation for Complicated Reconstructions

Category: Midfoot/Forefoot Introduction/Purpose: In the modern treatment of Charcot neuroarthropathy, beam screw fixation is an attractive alternative to plate and screw fixation because it minimizes the required exposure for implantation and supports the longitudinal columns of the foot from the inside out as a rigid yet load-sharing construct. Oversized implants risk metatarsal fracture and undersized implants risk implant fracture or impaired healing from mechanical instability. Our review of the scientific literature identified a lack of evidence regarding the aspects of metatarsal intramedullary canal morphology relevant to beam screw fixation. The purpose of the present study was to qualitatively and quantitatively describe metatarsal diaphyseal morphology. Methods: Twenty fresh-frozen adult cadaveric below knee specimens were utilized to assess the size and shape of the diaphysis of metatarsals 1-4. There were 10 male and 10 female specimens with a mean age of 75.8 years. No limbs had outward signs of prior injury/surgery, radiographic signs of Charcot neuroarthropathy or previous fracture. Metatarsals 1-4 were excised, cleaned of all soft tissue and then axially transected at the point of most narrow external diameter. The diaphyseal canal shape was categorized as round, oval, triangular, or pear. The widest distance between two endosteal cortical surfaces was measured. Results: Triangular endosteal canals were only found in the 1st metatarsal whereas the remainder of metatarsals canals were largely round or oval. The mean diameter of the 1st metatarsal was 9.08 ± 1.26 mm. The mean diameter of the 2nd metatarsal was 4.72 ± 0.82 mm. The mean diameter of the 3rd metatarsal was 4.53 ± 0.88 mm. The mean diameter of the 4th metatarsal was 4.51 ± 1.10 mm. Conclusion: Intramedullary fixation by internal beaming of the columns of the foot can provide anatomical alignment with stabile fixation in cases of patients with Charcot arthropathy. Our study has given the smallest average diameter for metatarsals one through 4. This data is helpful when determining what size fixation to choose to achieve the maximum screw-endosteal purchase for column beaming in Charcot reconstructions

Fibuloplasty: Distal fibular reconstruction performed in conjunction with ankle fusion conversion to implant arthroplasty

Ankle arthrodesis (AA) represents an effective, dependable procedure for the treatment of end-stage osteoarthritis of the ankle. While AA offers the benefits of pain relief and some preservation of function, it sacrifices ankle motion which over time may lead to progressive degeneration of the adjacent joints of the hindfoot. Historically, salvage options for failed or painful AA included revisional AA, tibiotalocalcaneal arthrodesis, pantalar arthrodesis, and amputation. More recently the conversion of AA to total ankle arthroplasty (TAA) has been shown to be a viable salvage option which, unlike early salvage options, restores motion and function to the ankle and may help to avoid the need for periarticular arthrodesis. A unique challenge faced with AA conversion to TAA includes instances where fibular resection was performed during the primary procedure. Previous studies have evaluated the viability of conversion to TAA in patients with AA and prior fibular resection, with most authors stating that the absence of the lateral malleolus is an absolute contraindication to TAA. In contrast, newer studies have reported success with various techniques to restore the lateral fibular strut and perform the conversion of AA to TAA. This case report describes a unique approach of AA conversion to TAA utilizing a custom, fibular prosthesis to restore lateral stability following prior AA with fibular resection