Bi-Radial Curvature Morphology of the Healthy Talus

Category: Ankle Introduction/Purpose: In order to design an implant for the ankle joint that mimics normal joint motion, the condylar geometry of the talus must be anatomically accurate. Previous attempts to describe the curvature of the talus have typically involved fitting single-radius arcs to the medial and lateral facets. The purpose of this investigation was to determine if the curvature of the medial and lateral sides of the talus can be more accurately described by dividing the condyles into anterior and posterior regions, thus creating bi-radial curves for both the medial and lateral sides of the talus. Methods: After IRB approval, 18 subjects (9 male, 9 female; mean age 34.5 years) underwent weight-bearing CT scans at mid- stance of simulated gait. All subjects were deemed to have a healthy right ankle by the surgeon investigator. CT images were used to generate 3D models of each talus. A coordinate system was defined and the articular surface of the talus was separated into four sections: medial-anterior (MA), medial-posterior (MP), lateral-anterior (LA) and lateral-posterior (LP). The curvature of each section was defined by selecting points on the articular surface at 10° intervals. The extent of each radius was 30° of arc and the magnitude of each radius was selected to minimize the gaps between the radii and the spline curve to define a best-fit bi-radial approximation to the spline curve using geometry that could be easily used to define the articular surface of the talus. Ratios of the aforementioned radii were calculated. Results: The average MA, MP, LA and LP radii were 18.3 mm, 26.6 mm, 21.5 mm and 25.1 mm, respectively. The medial (A/P), lateral (A/P), anterior (M/L) and posterior (M/L) radii ratios were 0.70, 0.87, 0.88 and 1.07, respectively. The anterior and posterior ratios were compared using a paired t-test and found to be statistically different (P=.019). Further, the data were compared against a hypothesized value of 1 using a one-tailed one-sample t-test. The anterior ratio was significantly lower than 1 (P=.014) while the posterior ratio was significantly greater (P=.037). On the lateral side, 83.3% of the subjects exhibited a larger posterior radius than anterior radius. Only one subject (5.6%) had a larger anterior radius than posterior radius on the medial side. Conclusion: This study shows that the radius increases in the sagittal plane from the anterior portion to the posterior portion of both the medial and lateral sides of the talus. Furthermore, the MA radius is smaller than the LA radius. Conversely, the MP radius is larger than the LP radius. These results substantiate the validity of an implant design that incorporates a condylar radius ratio that is smaller for the anterior dorsiflexion surface and greater for the posterior plantar flexion surface. Implants with more accurate anatomical geometry may allow for more normal kinematics and potentially prolong the life of the implant.

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Congenital club foot

Acta chirurgica iugoslavica ◽

10.2298/aci1001073v ◽

2010 ◽

Vol 57 (1) ◽

pp. 73-76 ◽

Cited By ~ 1

Author(s):

Z.S. Vukasinovic ◽

N.S. Slavkovic ◽

Z.M. Zivkovic ◽

V.D. Bascarevic

Keyword(s):

Surgical Treatment ◽

Club Foot ◽

Soft Tissues ◽

Plantar Flexion ◽

Lateral Side ◽

Foot Deformity ◽

Congenital Clubfoot ◽

Medial Side ◽

Success Of Treatment ◽

Bone Deformities

Congenital club foot is the most frequent foot deformity. It occurs in 1% of newborns, two times more frequently in boys, with family inheritance. Patoanatomicaly, entity consists of bone deformities, articular malpositions and soft tissues retraction. All these produce adduction of the forefoot and varus and equinovarus of the hindfoot. Lateral side of the foot is convex and medial side is concave. Forefoot is in adduction and plantar flexion in relation to the hindfoot. The heel is rotated medially which induces varus and eqinus of the foot. The aim of the treatment is to establish anatomically normal foot, painless, with moderate movements, which is suitable for normal shoes. At the beginning treatment is nonsurgical. If nonsurgical treatment fails further step should be surgical treatment. The success of treatment of congenital clubfoot depends on the time of diagnosis and treatment beginning.

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Leave it or fix it? How fixation of a small posterior malleolar fragment neutralizes rotational forces in trimalleolar fractures

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-021-03772-9 ◽

2021 ◽

Author(s):

Julia Evers ◽

Maren Fischer ◽

Michael Raschke ◽

Oliver Riesenbeck ◽

Alexander Milstrey ◽

...

Keyword(s):

Surface Area ◽

Articular Surface ◽

Plantar Flexion ◽

Weight Bearing ◽

Full Weight Bearing ◽

Neutral Position ◽

Screw Osteosynthesis ◽

Trimalleolar Fractures ◽

Group I ◽

Group Ii

Abstract Introduction This study investigated the effects of a small posterior malleolar fragment (PMF), containing less than 25% articular surface area, on ankle joint stability via computed tomography (CT) scanning under full weight bearing in a human cadaveric ankle fracture model. Materials and methods A trimalleolar fracture with a PMF of less than 25% articular surface area was created in 6 pairs of fresh-frozen human cadaveric lower legs. The specimens were randomized into 2 groups stabilized by internal fixation including a positioning screw for syndesmotic reconstruction. In Group I the PMF was addressed by direct screw osteosynthesis, whereas in Group II the fragment was not fixed. Six predefined distances within the ankle were measured under axial loading. CT scans of each specimen were performed in intact and fixated states in neutral position, dorsiflexion and plantar-flexion of the ankle. Results In plantar-flexion, significant differences were detected between the groups with regard to rotational instability. Group II demonstrated a significantly increased inward rotation of the fibula compared with Group I. No significant differences were detected between the groups for each one of the measured distances in any of the three foot positions. Conclusions Additional reduction and fixation of a small PMF seems to neutralize rotational forces in the ankle more effectively than a sole syndesmotic screw. Clinically, this becomes relevant in certain phases of the gait cycle. Direct screw osteosynthesis of a small PMF stabilizes the ankle more effectively than a positioning screw.

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Unexpected Injury During Jumping Exercise

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967114s00192 ◽

2014 ◽

Vol 2 (11_suppl3) ◽

pp. 2325967114S0019

Author(s):

Bahattin Kemah ◽

Afşar Timuçin Özkut ◽

İrfan Esenkaya ◽

Kaya Hüsnü Akan ◽

İsmail Türkmen

Keyword(s):

Plantar Flexion ◽

Weight Bearing ◽

Joint Stiffness ◽

Lateral Side ◽

Second Phase ◽

Return To Sports ◽

Aofas Score ◽

Subtalar Dislocation ◽

Early Return ◽

Partial Weight

Objectives: The purpose of this case presentation is to report the results of physical therapy and conservative treatment of a rare clinical entity, isolated subtalar dislocation that occurred during triple jumping during which maximum compression forces act on the foot. Methods: A 20 years old national triple jumping athlete fell during daily sports exercises which consist of jumping to the medial and lateral side trying to catch a sports ball bouncing from the wall while his right foot was inverted and in plantar flexion. The patient was admitted to our emergency service. The physical examination revealed that the hindfoot was displaced medially. The neurological examination was intact and there was no sign of dermal injury. After the radiological examination the diagnosis was isolated subtalar dislocation. The dislocation was reduced with longitudinal traction with the knee was in flexion. The MR imaging did not reveal any chondral damage. The choice of treatment was conservative. After 4 days as the edema subsided, a short leg cast was applied for four weeks. Then, the cast was removed and active range of motion exercises were initiated. The first 25 days consisted of exercises with rubber band, bottle rolling under the foot. The second phase included walking in the pool and the patient was asked to start weight bearing partially. The patient went on with proprioception and strengthening exercises. Later, kinesiologic taping was also added to the therapy. He changed his jumping foot and started his routine training program with the team after 170 days. He participated in his first official competition 16 months after the injury. At the 28. month, he broke the national record in the National Interuniversities Athletics Games. 2 months later, he got the third place in the World Athletics Championship. Results: The follow up period was 4 years. AOFAS score was 76 at second month and 83 at the fourth. At the first and at the fourth year, AOFAS score was 100. No dermal lesions or joint stiffness or signs of arthritis was observed. Avascular necrosis of talus or complex regional pain syndrome was not encountered. Conclusion: Early return to sports activities is of tantamount importance as early reduction. Reduction can be carried out in an open or closed manner. For prevention of joint stiffness, immobilization period has to be short and active ROM exercises has to be initiated with partial weight bearing as soon as the joint stability and strength is adequate.

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Anatomy of the Intermetatarsal Facets of the Fourth and Fifth Metatarsals

Foot & Ankle Orthopaedics ◽

10.1177/2473011420975709 ◽

2021 ◽

Vol 6 (1) ◽

pp. 247301142097570

Author(s):

Mossub Qatu ◽

George Borrelli ◽

Christopher Traynor ◽

Joseph Weistroffer ◽

James Jastifer

Keyword(s):

Articular Cartilage ◽

Digital Imaging ◽

Articular Surface ◽

Implant Design ◽

Joint Surface ◽

Fracture Classification ◽

Articular Damage ◽

Metatarsal Fracture ◽

Metatarsal Fractures ◽

The Mean

Background: The intermetatarsal joint between the fourth and fifth metatarsals (4-5 IM) is important in defining fifth metatarsal fractures. The purpose of the current study was to quantify this joint in order to determine the mean cartilage area, the percentage of the articulation that is cartilage, and to give the clinician data to help understand the joint anatomy as it relates to fifth metatarsal fracture classification. Methods: Twenty cadaver 4-5 IM joints were dissected. Digital images were taken and the articular cartilage was quantified by calibrated digital imaging software. Results: For the lateral fourth proximal intermetatarsal articulation, the mean area of articulation was 188 ± 49 mm2, with 49% of the area composed of articular cartilage. The shape of the articular cartilage had 3 variations: triangular, oval, and square. A triangular variant was the most common (80%, 16 of 20 specimens). For the medial fifth proximal intermetatarsal articulation, the mean area of articulation was 143 ± 30 mm2, with 48% of the joint surface being composed of articular cartilage. The shape of the articular surface was oval or triangular. An oval variant was the most common (75%, 15 of 20 specimens). Conclusion: This study supports the notion that the 4-5 IM joint is not completely articular and has both fibrous and cartilaginous components. Clinical Relevance: The clinical significance of this study is that it quantifies the articular surface area and shape. This information may be useful in understanding fifth metatarsal fracture extension into the articular surface and to inform implant design and also help guide surgeons intraoperatively in order to minimize articular damage.

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OP0177 PROPERTIES AND LOCATIONS OF COLOR-CODED DUAL ENERGY CT LESIONS IN GOUT PATIENTS – A SYSTEMATIC EVALUATION

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2020-eular.1757 ◽

2020 ◽

Vol 79 (Suppl 1) ◽

pp. 110.1-110

Author(s):

S. Nysom Christiansen ◽

F. C. Müller ◽

M. Ǿstergaard ◽

O. Slot ◽

J. Møllenbach Møller ◽

...

Keyword(s):

Weight Bearing ◽

Dual Energy ◽

Joint Fluid ◽

Knee Joints ◽

Systematic Evaluation ◽

Tibialis Posterior ◽

Dual Energy Ct ◽

Medial Side ◽

Diagnostic Potential ◽

Subgroup Analyses

Background:Dual energy CT (DECT) has diagnostic potential in gout patients. DECT can automatically colour-code presumed urate deposits based on radiodensity (Hounsfield Units, HU) and DECT ratio (difference in attenuation between high and low kV series) of lesions. However, other materials may imitate properties of urate deposits, most importantly calcium-containing material, dense tendons and artefacts, which may lead to misinterpretations. The characteristics of DECT lesions in gout patients have not yet been systematically investigated.Objectives:To evaluate the properties and locations of colour-coded DECT lesions in gout patients.Methods:DECT were performed in patients with suspected gout. Patients were separated into gout and non-gout patients based on joint fluid microscopy findings. DECT of the hands, knees and feet were performed using default gout settings and colour-coded lesions were registered. Only location-relevant lesions were analysed (e.g. nail bed artefacts excluded). Mean density (mean of HU at 80 kV and Sn150 kV), mean DECT ratio, size and location of each lesion was determined.Subgroup analysis was performed post-hoc evaluating potential differences in properties and locations of lesions. Lesions were separated into groups according to properties (Figure 1, grey box): 1)Size—to separate artefacts characterised by small volume (possible artefacts). 2)DECT ratios—to separate calcium-containing material characterised by high DECT ratio (possible calcium-containing material). 3)Density—to separate dense tendons characterised by low DECT ratio and low HU values (possible dense tendons). Lesion fulfilling all urate characteristics (large volume, low DECT ratio, high density) were labelleddefinite urate deposits. Finally, for non-gout patients, properties ofnon-gout urate-imitation lesions(properties asdefinite urate deposits) were analysed.Results:In total, 3918 lesions (all lesions) were registered in gout patients (n=23), with mean DECT ratio 1.06 (SD 0.13), median density 160.6 HU and median size 6 voxels (Figure 1, blue box). Lesions were seen in all analysed joints, most frequently MTP1 joints (medial side), knee joints and midtarsal joints (Figure 2a). Tendon affections were also common, especially in the knee tendons (patella and quadriceps), malleolus-related tendons (e.g. peroneus and tibialis posterior) and the Achilles tendons (Figure 2a).Subgroup analyses showed thatdefinite urate deposits(figure 2b) were found at the same locations asall lesionin gout patients (figure 2a), with the four most common sites being MTP1 joints, midtarsal joints, and quadriceps and patella tendons (Figure 2b).Possible dense tendonlesions had a mean HU value of 156.5 HU—markedly higher than expected for dense tendons (<100HU)—and lesion-locations were similar todefinite urate deposits(data not shown), indicating that they primarily consisted of true urate deposits. In contrast,possible calcium-containing materialandnon-gout urate-imitating lesionshad distinctly different properties (ratios 1.33 and 1.20, respectively) (Figure 1, yellow and orange box). Furthermore, the locations of these lesions were different fromdefinite urate depositssince they were primarily found in a few weight-bearing joints (knee, midtarsal and talocrural including malleolus regions) and tendons (Achilles and quadriceps), whereas no lesions were found in either MTP1 joints or patella tendons (figure 2c).Conclusion:DECT color-coded lesions in gout patients are heterogeneous in properties and locations. Subgroup analyses found that locations such as MTP1 joints and patella tendons were characterised by almost only showingdefinite urate deposits. A sole focus on these regions in the evaluation of gout patients may therefore improve specificity of DECT scans.Disclosure of Interests:Sara Nysom Christiansen Speakers bureau: SNC has received speaker fees from Bristol Myers Squibb (BMS) and General Electric (GE)., Felix C Müller Employee of: Siemens Healthineers., Mikkel Ǿstergaard Grant/research support from: AbbVie, Bristol-Myers Squibb, Celgene, Merck, and Novartis, Consultant of: AbbVie, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo Nordisk, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB, Speakers bureau: AbbVie, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo Nordisk, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB, Ole Slot: None declared, Jakob Møllenbach Møller: None declared, Henrik F Børgesen: None declared, Kasper K Gosvig: None declared, Lene Terslev Speakers bureau: LT declares speakers fees from Roche, MSD, BMS, Pfizer, AbbVie, Novartis, and Janssen.

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Is postoperative non-weight-bearing necessary? INWN Study protocol for a pragmatic randomised multicentre trial of operatively treated ankle fracture

Trials ◽

10.1186/s13063-021-05319-0 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Ramy Khojaly ◽

Ruairí Mac Niocaill ◽

Muhammad Shahab ◽

Matthew Nagle ◽

Colm Taylor ◽

...

Keyword(s):

Ankle Fracture ◽

Multicentre Trial ◽

Short Form ◽

Plantar Flexion ◽

Weight Bearing ◽

Ankle Fractures ◽

Hospital Length Of Stay ◽

Complication Rates ◽

Fracture Patterns ◽

Randomised Controlled

Abstract Background Postoperative management regimes vary following open reduction and internal fixation (ORIF) of unstable ankle fractures. There is an evolving understanding that extended periods of immobilisation and weight-bearing limitation may lead to poorer clinical outcomes. Traditional non-weight-bearing cast immobilisation may prevent loss of fixation, and this practice continues in many centres. The purpose of this trial is to investigate the safety and efficacy of immediate weight-bearing (IWB) and range of motion (ROM) exercise regimes following ORIF of unstable ankle fractures with a particular focus on functional outcomes and complication rates. Methods A pragmatic randomised controlled multicentre trial, comparing IWB in a walking boot and ROM within 24 h versus non-weight-bearing (NWB) and immobilisation in a cast for 6 weeks, following ORIF of all types of unstable adult ankle fractures (lateral malleolar, bimalleolar, trimalleolar with or without syndesmotic injury) is proposed. All patients presenting to three trauma units will be included. The exclusion criteria will be skeletal immaturity and tibial plafond fractures. The three institutional review boards have granted ethical approval. The primary outcome measure will be the functional Olerud-Molander Ankle Score (OMAS). Secondary outcomes include wound infection (deep and superficial), displacement of osteosynthesis, the full arc of ankle motion (plantar flexion and dorsal flection), RAND-36 Item Short Form Survey (SF-36) scoring, time to return to work and postoperative hospital length of stay. The trial will be reported in accordance with the CONSORT statement for reporting a pragmatic trial, and this protocol will follow the SPIRIT guidance. Discussion Traditional management of operatively treated ankle fractures includes an extended period of non-weight-bearing. There is emerging evidence that earlier weight-bearing may have equivocal outcomes and favourable patient satisfaction but higher wound-related complications. These studies often preclude more complicated fracture patterns or patient-related factors. To our knowledge, immediate weight-bearing (IWB) following ORIF of all types of unstable ankle fractures has not been investigated in a controlled prospective manner in recent decades. This pragmatic randomised-controlled multicentre trial will investigate immediate weight-bearing following ORIF of all ankle fracture patterns in the usual care condition. It is hoped that these results will contribute to the modern management of ankle fractures. Trial registration ISRCTN Registry ISRCTN76410775. Retrospectively registered on 30 June 2019.

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Differential Contribution of the Medial and the Lateral Side of the Joint to Symptoms in Knee Osteoarthritis: A Radiographic and Laboratory Analysis in the Nagahama Study

Cartilage ◽

10.1177/19476035211025817 ◽

2021 ◽

pp. 194760352110258

Author(s):

Kazuya Nigoro ◽

Hiromu Ito ◽

Tomotoshi Kawata ◽

Shinichiro Ishie ◽

Yugo Morita ◽

...

Keyword(s):

Knee Osteoarthritis ◽

Clinical Outcomes ◽

Knee Pain ◽

High Sensitivity ◽

Analysis Of Covariance ◽

Radiographic Evaluation ◽

Radiographic Feature ◽

Lateral Side ◽

Cross Sectional ◽

Medial Side

Objective: This cross-sectional study aimed to explore the differences of the medial and lateral sides of the knee joint and precise radiographic abnormalities in contribution to the knee pain and clinical outcomes. Design: Participants 60 years or older who underwent radiographic evaluation were included. Knee radiography was assessed using grading systems of the Osteoarthritis Research Society International (OARSI) atlas. The Japanese Knee Osteoarthritis Measure (JKOM) was evaluated as clinical outcomes. Serum high-sensitivity C-reactive protein (hsCRP) was used to evaluate systemic inflammation. We divided the participants into normal, medial-, lateral-, and medial & lateral-OA types and compared their JKOM using an analysis of covariance. Furthermore, we analyzed the relationship between the knee pain and stiffness of JKOM and the grading of each radiographic feature using a multiple regression model. Results: Lateral- and medial & lateral-OA groups had a significantly worse symptoms in the total and the pain score, especially in movement subscales, in JKOM score. Lateral-OA groups had higher hsCRP than medial-OA group. Multivariate analysis showed that medial joint space narrowing (JSN), and lateral femoral and tibial osteophytes significantly affected knee pain (adjusted odds ratios: 1.73, 1.28, and 1.55, respectively). The radiographic changes are associated with pain more in JSN in the medial side and osteophytes in the lateral side. Conclusion: Lateral- and medial & lateral-OA groups showed worth symptom. In addition, medial JSN and lateral osteophytes have potent effects on the knee pain.

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Medial malleolar osteotomy for intralesional curettage and bone grafting of primary aneurysmal bone cyst of the talus

BMJ Case Reports ◽

10.1136/bcr-2021-242452 ◽

2021 ◽

Vol 14 (5) ◽

pp. e242452

Author(s):

Sujit Tripathy ◽

Paulson Varghese ◽

Sibasish Panigrahi ◽

Lubaib Karaniveed Puthiyapura

Keyword(s):

Aneurysmal Bone Cyst ◽

Cystic Lesion ◽

Articular Surface ◽

Weight Bearing ◽

Bone Cyst ◽

Lytic Lesion ◽

Intralesional Curettage ◽

Medial Malleolar Osteotomy ◽

Fluid Levels

Access to the cystic lesion of the talar body without damage to the articular surface is difficult. This case report is about a 23-year-old man who had a symptomatic huge cystic lesion in the left-sided talus bone. Radiograph and CT scan showed an expansile lytic lesion within the talar body. The MRI revealed a well-defined lesion with fluid-fluid levels. The needle biopsy aspirate was haemorrhagic, and hence a diagnosis of the aneurysmal bone cyst was made. As the lesion was beneath the talar dome with an intact neck and head, a medial approach with medial malleolar osteotomy was performed. The lesion was curetted out, and the cavity was filled up with a morselised bone graft. The limb was splinted for 6 weeks, and complete weight bearing was started after 3 months. At 1-year follow-up, the lesion was found to be healed up, and the patient was pain-free with no recurrence.

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Effects of Unweighting on Gait Kinematics During Walking on a Lower-Body Positive-Pressure Treadmill in Patients with Hip Osteoarthritis

10.21203/rs.3.rs-20817/v4 ◽

2021 ◽

Author(s):

Yoshiaki Kataoka ◽

Tomohiro Shimizu ◽

Ryo Takeda ◽

Shigeru Tadano ◽

Yuki Saito ◽

...

Keyword(s):

Rating Scale ◽

Plantar Flexion ◽

Weight Bearing ◽

Hip Osteoarthritis ◽

The Body ◽

Lower Limbs ◽

Positive Pressure ◽

Control Group ◽

Lower Body ◽

Gait Kinematics

Abstract Background: Hip osteoarthritis (OA) is a musculoskeletal condition that makes walking difficult due to pain induced by weight-bearing activities. Treadmills that support the body weight (BW) reduce the load on the lower limbs, and those equipped with a lower-body positive-pressure (LBPP) device, developed as a new method for unweighting, significantly reduce pain in patients with knee OA. However, the effects of unweighting on gait kinematics remain unclear in patients with hip OA. Therefore, we investigated the effects of unweighting on kinematics in patients with hip OA during walking on a treadmill equipped with an LBPP device. Methods: A total of 15 women with hip OA and 15 age-matched female controls wore a three-dimensional (3-D) motion analysis system and walked at a self-selected speed on the LBPP treadmill. Data regarding self-reported hip pain using a numeric rating scale (NRS) in which the scores 0 and 10 represented no pain and the worst pain, respectively, under three different BW conditions (100%, 75%, and 50%) were collected. Moreover, 3-D peak joint angles during gait under each condition were calculated and compared. Results: In the hip OA group, the NRS pain scores at 50% and 75% BW conditions significantly decreased compared with that at 100% BW condition (50%, P=0.002; 75%, P=0.026), and the peak hip extension angle decreased compared with that in the healthy controls (P=0.044). In both groups, unweighting significantly decreased the peak hip (P<0.001) and knee (P<0.001) flexion angles and increased the peak ankle plantar flexion angle (P<0.001) during walking. Conclusions: Unweighting by the LBPP treadmill decreased pain in the hip OA group but did not drastically alter the gait kinematics compared with that in the control group. Therefore, regarding the use of the LBPP treadmill for patients with hip OA, clinicians should consider the benefits of pain reduction rather than the kinematic changes.

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Assessment of Acetabulum Deformity During Preoperative Planning for Hip Arthroplasty

Traumatology and Orthopedics of Russia ◽

10.21823/2311-2905-2019-25-3-153-164 ◽

2019 ◽

Vol 25 (3) ◽

pp. 153-164

Author(s):

D. V. Martynenko ◽

V. P. Voloshin ◽

L. A. Sherman ◽

K. V. Shevyrev ◽

S. A. Oshkukov ◽

...

Keyword(s):

Acetabular Component ◽

Hip Joint ◽

Preoperative Planning ◽

Bone Defects ◽

Lateral Side ◽

X Rays ◽

Two Dimensional ◽

Acetabular Coverage ◽

Anatomical Features ◽

Medial Side

Purpose of the study — to improve the two-dimensional planning of total hip joint arthroplasty to ensure precise positioning of the acetabular component in the deformed acetabulum. Materials and methods. Features of roentgenological anatomy of acetabulum and its coverage were studied on 1058 hip joint x-rays in the AP view in accordance with the procedure developed by the authors to define acetabular square — the site of standard positioning of a spherical femoral head in the acetabulum or of a hemispherical acetabular component. The method consisted of identifying the apex of “teardrop” figure; the most lateral points of the pelvic terminal line and roof of the acetabulum; superior part of the acetabular cavity; medial and inferior points of acetabular coverage, and building the sides of acetabular square — medial, inferior, lateral and superior boundary lines. Connection of “teardrop” apex and lateral point of the pelvic terminal line formed the medial side of acetabular square, and a perpendicular to that line drawn through the “teardrop” apex to its inferior side. The lateral side was drawn either through the intersection of the ascending diagonal line — bisector from the top of the “teardrop” figure with the contour of the acetabulum roof, or was a part of the projection of the most lateral point of the acetabular roof on the inferior side of the square. The superior side was a perpendicular connecting the intersection of the ascending diagonal and lateral bounding lines with the medial side of the acetabular square. The area of the deformed acetabular cavity located outside of the acetabular square was assessed as the acetabular defect. Results. Method of defining the acetabular square allowed to identify types of ratios between acetabular cavity and acetabular coverage in transverse (9 types) and longitudinal (7 types) direction. Combination of transverse ratio of acetabular cavity and coverage with longitudinal type allowed to define the options of acetabular deformities in two-dimensional view. The authors identified 25 types of acetabular deformities. Bone defects of acetabular walls were of the major importance among all anatomical features. Cranial defect of acetabulum was observed in 450 cases, medial wall defect — in 38 cases, defect including cranial and medial areas — in 7 cases. Conclusion. The method suggested by the authors to determine acetabular square and acetabular deformity variations allows to screen the anatomical features of the acetabulum during two-dimensional preoperative planning and to make an informed decision on the need to use other planning techniques. The type of acetabular deformity identified during preoperative planning allows to elaborate the indications for replacement of acetabular bone defects and/or resection of acetabular osteophytes.

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