Stefan Meissner

Matrix-associated stem cell transplantation (MAST) in chondral defects of the ankle is safe and effective – 2-year-followup in 130 patients

BACKGROUND The aim of the study was to assess the 2-year-follow-up of matrix-associated stem cell transplantation (MAST) in chondral defects of the ankle. METHODS In a prospective consecutive non-controlled clinical follow-up study, all patients with chondral defect that were treated with MAST from October 1, 2011 to July 31, 2013 were analyzed. Size and location of the chondral defects, method-associated problems and the Visual Analogue Scale Foot and Ankle (VAS FA) before treatment and at follow-up were analyzed. Stem cell-rich blood was harvested from the ipsilateral pelvic bone marrow and centrifuged (10min, 1500rpm). The supernatant was used to impregnate a collagen I/III matrix (Chondro-Gide). The matrix was fixed into the chondral defect with fibrin glue. RESULTS One hundred and forty-four patients with 150 chondral defects were included in the study. The age of the patients was 35 years on average (range, 12-68 years), 85 (59%) were male. The VAS FA before surgery was 48.5 on average (range, 16.5-78.8). The defects were located as follows, medial talar shoulder, n=62; lateral talar shoulder, n=66 (medial and lateral talar shoulder, n=6), tibia, n=22. The defect size was 1.6cm2 on average (range, .6-6cm2). 130 patients (90%) completed 2-year-follow-up. The VAS FA improved to an average of 87.5 (range, 62.1-100; t-test (comparison with preoperative scores), p=.01). CONCLUSIONS MAST led to improved and high validated outcome scores. No method related complications were registered. Even though a control group is missing, we conclude that MAST is a safe and effective method for the treatment of chondral defects of the ankle.

Combination of PedCAT Weightbearing CT With Pedography Assessment of the Relationship Between Anatomy-Based Foot Center and Force/Pressure-Based Center of Gravity

Background: A customized pedography sensor (Pliance; Novel, Munich, Germany) was inserted into a pedCAT (Curvebeam, Warrington, PA). The aim of this study was to analyze the relative position of the anatomical foot center (FC) and the pedographic center of gravity (COG). The hypothesis was that FC should be a good predictor of mediolateral position of COG but not longitudinal since hindfoot anatomy allows free anteroposterior movement but limited mediolateral movement. Methods: In 90 patients (180 feet), a pedCAT scan with simultaneous pedography with full weightbearing in a standing position was performed. The morphology-based definition of the FC was performed with the pedCAT data following the Torque Ankle Lever Arm System (TALAS) algorithm. The force/pressure-based COG was defined with the pedography data using a software-based algorithm. The distance between FC and COG and the direction of a potential shift (distal-proximal, mediolateral) was measured and analyzed. COG motion during data acquisition was recorded and analyzed. Mean age of patients was 53.8 (range, 17-84) years, and 57 (63%) were female. Results: The distance between FC and COG was 28.7 mm on average (range, 0-60). FC was distal to COG in 175 feet (97%; mean, 27.5 mm; range, –15 to 60) and lateral in 112 feet (62%; mean, 2.0 mm; range, –18 to 20). Conclusions: There was a constant and major distal longitudinal shift of COG relative to FC and an inconstant minor mediolateral shift. Clinical Relevance: The data might be taken into consideration for planning and follow-up in foot and ankle surgery.

Matrix-associated stem cell transplantation (MAST) in chondral defects of the 1st metatarsophalangeal joint is safe and effective—2-year-follow-up in 20 patients

The aim of the study was to assess the 2-year-follow-up of matrix-associated stem cell transplantation (MAST) in chondral defects of the 1st metatarsophalangeal joint (MTPJ). In a prospective consecutive non-controlled clinical follow-up study, 20 patients with 25 chondral defect at the 1st MTPJ that were treated with MAST from October 1st, 2011 to March, 30th, 2013 were analysed. The size and location of the chondral defects range of motion (ROM), and the Visual-Analogue-Scale Foot and Ankle (VAS FA) before treatment and at follow-up were registered. Stem cell-rich blood was harvested from the ipsilateral pelvic bone marrow and centrifuged (10min, 1500 RPM). The supernatant was used to impregnate a collagen I/III matrix (Chondro-Guide). The matrix was fixed into the chondral defect with fibrin glue. The age of the patients was 42 years on average (range, 35-62 years). The VAS FA before surgery was 50.5 (range, 18.3-78.4). The defects were located as follows, dorsal metatarsal head, n=12, plantar metatarsal head, n=5, dorsal & plantar, n=8 (two defects, n=5). The defect size was 0.7cm2 (range, .5-2.5cm2). ROM was 10.3/0/18.8° (dorsal extension/plantar flexion). All patients completed 2-year-follow-up. VAS FA improved to 91.5 (range, 74.2-100; t-test, p<.01). ROM improved to 34.5/0/25.5 (p=.05). The surgical treatment including MAST led to improved clinical scores and ROM. Even though a control group is missing, we conclude that MAST is a safe and effective method for the treatment of chondral defects of the 1st MTPJ.

Combination of PedCAT with Pedography Shows Relationship of Morphology (Bone) Based Foot Center (FC) and Force/Pressure Based Center of Gravity (COG)

Category: Basic Sciences/Biologics Introduction/Purpose: PedCAT (Curvebeam, Warrington, USA) is a technology for 3D-imaging with full weight bearing which has been proven to exactly visualize the 3D-bone position. Center of gravity (COG) and Foot Center (FC) are discussed to be important parameters for corrections/fusion around the hindfoot and for total ankle replacement. For this study a customized pedography sensor (Pliance, Novel, Munich, Germany) was inserted into the pedCAT. The aim of this study was to analyze difference of morphology (Bone/PedCAT) based FC and Force/Pressure (Pedography) based COG. Motion of COG during PedCAT/Pedography scan should also be registered and analyzed. Methods: In a prospective consecutive study starting November 28, 2016, 36 patients / 72 feet were included. Inclusion criteria were 18 years of age or older, and indication for PedCAT scan based on the local standard. A pedCAT scan with simultaneous pedography with full weight bearing in standing position was performed. The morphology based definition of the FC was performed with the pedCAT data following the TALAS algorithm. This algorithm takes different bony landmarks (Posterior calcaneal process, center of talar dome/tibial plafond, metatarsal heads) into consideration and calculates the FC. The force/pressure based COG was defined with the pedography data using a software based algorithm. The distance between FC and COG and the direction of a potential shift (distal-proximal; medial lateral) was measured and analyzed. COG motion during data acquisition was recorded and analyzed. Results: Mean age of patients was 54.5 (range, 27-80) years, 27 (75%) were female. COG motion was 1.4 mm on average (range, 0-4.8 mm). The distance between FC and COG was 22.6 mm on average (range, 5-52). FC was distally to COG in all feet (mean, 27.4 mm; range, 3-50), and laterally in 49 feet (68%; shift 0 mm in remaining feet; mean for all feet, 3.3 mm; range, 0-12). No difference between right and left side occurred (t-test, each p>.05). Conclusion: COG is not relevantly moving during combined PedCAT/Pedography scan. There is a difference between FC and COG. This expected finding was quantified with this study. There is a typical/standard shift between COG and FC in the investigated 32 subjects / 64 feet (26 mm distally and 3 mm laterally on average) which might allow for prediction of COG based on FC without additional pedography. Definition of COG might be taken into consideration for planning and followup for corrections/fusion around the hindfoot and for total ankle replacement.

Matrix-Associated Stem Cell Transplantation (MAST) in Chondral Defects of the Ankle is Safe and Effective - 5-Year-Followup

Category: Ankle, Arthroscopy, Sports Introduction/Purpose: The aim of the study was to assess the 5-year-follow-up of matrix-associated stem cell transplantation (MAST) in chondral defects of the ankle. Methods: In a prospective consecutive non-controlled clinical follow-up study, all patients with chondral defect that were treated with MAST from April1 2009 to September 30, 2011 were analyzed. Size and location of the chondral defects and the Visual- Analogue-Scale Foot and Ankle (VAS FA) before treatment and at follow-up were analysed. Stem cell-rich blood was harvested during the procedure from the ipsilateral pelvic bone marrow with a Jamshidi needle (10 x 3 mm, Cardinal, Dublin, OH, USA) and a special syringe (Arthrex-ACP, Arthrex, Naples, FL, USA) through a stab incision. The syringe was centrifuged (10 minutes, 1,500 rotations per minute). The supernatant was used to impregnate a collagen I/III matrix (Chondro-Gide, Geistlich, Wollhusen, Switzerland) that was cut to the size of the cartilage defect roughly before and definitely after. The matrix with stem cells was fixed into the chondral defect with fibrin glue (Tissucoll, Deerfield, IL, USA). Results: Sixty-six patients with 69 chondral defects were included in the study. The age of the patients was 35 years on average (range, 12-64 years). VAS FA before surgery was 48.9 on average (range, 16.5-75.9). The defects were located as follows, medial talar shoulder, n=28; lateral talar shoulder, n=28 (medial and lateral talar shoulder, n=3), tibia, n=3. The defect size was 1.4 cm2 on average (range, .6 - 6 cm2). 60 patients (91%) completed 5-year-follow-up. No patient was converted to fusion or total ankle replacement. The VAS FA improved to an average of 78.2 (range, 60.8-100; p=.01). Conclusion: MAST led to improved and high validated outcome scores at 5-year-followup. No method related complications were registered. Even though a control group is missing, we conclude that MAST is an effective method mid-term for the treatment of chondral defects of the ankle.

Tibiotalocalcaneal Arthrodesis with a Retrograde Triple Bending Nail - Results of 200 Cases

Category: Ankle, Ankle Arthritis, Hindfoot Introduction/Purpose: The aim of the study was to analyse the clinical aspects including minimum 1-year-followup of tibiotalocalcaneal arthrodeses (TTCA) with a triple-bend retrograde intramedullary nail (A3, Stryker, Airview Boulevard, MN, USA). Methods: In a prospective consecutive non-controlled clinical followup study, all patients with TTCA using A3 from October 18th, 2011 to October 10th, 2015 were analyzed. The time and accuracy of the alignment and implant position (Visual analogue scale, 0-10) for implant placement, complications, radiological fusion, and Visual Analogue Scale Foot and Ankle (VAS FA) were recorded. Fusion (=50% bony bridge at ankle and subtalar joints assessed on radiographs) was assessed at 6, 9, 12 weeks, then latest follow-up. VAS FA was recorded at latest follow-up. Results: 200 cases were included (age, 59.3 (22-83) years; VAS FA, 31.9 (0-79.3)). Indications were specified as follows (multiple possible): osteoarthritis, n=182 (91%); instability, n=48 (24%); deformity, n=154 (77%), failed total ankle replacement, n=12 (6%); failed previous fusion, n=15 (8%), diabetes, n=28 (14%). The time for implant preparation and positioning was 17.2 (5-32) minutes. The accuracy of alignment and implant position was 9.4 (7 - 10). Complications were registered in 12 (6%; n=6 (3%) infection, n=6 (3%) wound healing delay. One hundred and sixty-eight (84%) patients completed follow-up at 32 (12-60) months: VAS FA 60.4 (t-test (comparison with preoperative scores), p=.01)), fusion rate 96%. Conclusion: TTCA with the A3 implant system showed accurate correction and implant position. Thirty-two month (average) followup of 168 patients (84%) showed good clinical outcome scores and 96% fusion rate.

Two-Year-Followup in 20 Patients After Matrix-Associated Stem Cell Transplantation (MAST) in Chondral Defects of the 1st Metatarsophalangeal Joint

Category: Other Introduction/Purpose: For treatment of chondral defects, matrix-associated stem cell transplantation (MAST) is a modification of autologous matrix-induced chondrogenesis (AMIC) with a potential higher concentration of stem cells due to harvesting fluid at the bone marrow and in-vitro processing. The aim of the study was to assess the 2-year-followup of MAST in chondral defects of the 1st MTP. Methods: In a prospective consecutive non-controlled clinical follow-up study, all patients with chondral defect that were treated with MAST from April 1st 2009 to March, 30th, 2013 were analyzed. Patients with bilateral treatment or with MAST at more than one joint surface were excluded from the study. The size and location of the chondral defects, method-associated problems and the Visual-Analogue-Scale Foot and Ankle (VAS FA) and range of motion were registered and analyzed. MAST was performed as a single open procedure including debridement and microfracturing of the chondral defects. Stem cell- rich blood was harvested during the procedure from the ipsilateral pelvic bone marrow and was centrifuged (10 minutes, 1,500 RPM). The supernatant was used to impregnate a collagen I/III matrix (Chondro-Guide®, Geistlich, Baden-Baden, Germany) that was cut to the size of the defect before. The matrix with stem cells was fixed into the chondral defect with fibrin glue (Tissucoll, Deerfield, USA). Results: Twenty-five chondral defects in 20 patients were included in the study. The age of the patients was 42 years on average (range, 35-62 years), 14 (70%) were male. The VAS FA before surgery was 50.5 on average (range, 18.3-78.4). The defects were located as follows, medial metatarsal head, n=7; lateral metatarsal head, n=18 (medial and lateral metatarsal head, n=5). The defect size was 0.7 cm2 on average (range, .4 - 1.5 cm2). ROM was 10.2/0/18.8° on average. All patients completed 2-year- followup. No method related complications were registered. The VAS FA improved to an average of 91.5 (range, 74.2-100; t-test (comparison with preoperative scores), p=.01). ROM improve to 32.5/0/25.5 one average (p=.05). Conclusion: MAST led to good clinical scores and improved range of motion. No complications were registered. Even though a control group is missing, we conclude that MAST is a safe and effective method for the treatment of chondral defects of the 1st MTP joint. The main advantage of MAST in comparison with ACI and MACI is the single procedure methodology. The advantage in comparison with AMIC is the potential higher concentration of stem cells. It remains unclear if this method is superior to AMIC, and what kind of tissue is created.

Tibiotalocalcaneal Fusion with a Retrograde Triple Bending Nail - 2-Year-Followup Results

Category: Hindfoot Introduction/Purpose: Retrograde nails are one option for fixation in tibiotalocalcaneal fusion (TTCF). Most actual designs include straight or distally lateral bent nails that could have a short bone purchase in the calcaneus with potentially limited stability and resulting delayed union or nonunion. A nail with additional distal posterior bend for longer purchase in the calcaneus for increased stability was developed (A3, Small Bone Innovation, Morrisville, PA, USA). The aim of this study was to investigate the clinical application and short-term clinical followup. Methods: In a prospective consecutive non-controlled clinical followup study, all patients with TTCF using A3 from October 18th, 2011 to April 29th, 2013 were analyzed. The specific shape of the nail includes a distal double bend; one posterior (15°) and one lateral (10°). Posterolateral approach to the ankle and subtalar joint were utilized. The times and accuracy of the alignment and implant position (Visual analogue scale, 0-10) for implant placement, complications, radiological fusion, and Visual Analogue Scale Foot and Ankle (VAS FA) were recorded. Time for implant position comprised placement of the nail, 4 locking screws and compression with the compression screw. Calcaneal pitch and hindfoot angles were measured, pre-, postoperatively and at 24 months. Fusion (≥50% bony bridge at ankle and subtalar joints assessed on radiographs) was assessed at 6, 9, 12 weeks, 12, 24 months. VAS FA was recorded at 24 months. Results: 66 cases/feet were included (age, 58.5 (22-80) years; VAS FA, 29.6 (0-69)). Indications were specified as follows (multiple indications possible): osteoarthritis, n=43 (65%); instability, n=12 (18%); deformity, n=36 (55%), failed total ankle replacement, n=4 (6%); failed previous fusion, n=9 (14%), diabetes mellitus, n=5 (8%). The time for implant preparation and positioning was 17.5 (5-31) minutes. The accuracy of alignment and implant position was 9.4 (7.5 - 10). Sixty (91%) patients completed follow-up: VAS FA 59.9 (t-test (comparison with preoperative scores), p=.01)), fusion rate 100%, high accuracy of correction and implant position. The deviation of the measured angles from the desired angles (hindfoot angle, 5° valgus; calcaneal pitch angle, 20°) were lower at follow-up than pre-operatively (each p < 0.001). Conclusion: TTCA with the A3 implant system showed accurate correction and implant position. Two-year-follow-up in 60 patients showed good clinical outcome scores and 100% fusion rate.