430 Indian Journal of Forensic Medicine & Toxicology, July-September 2021, Vol. 15, No. 3 Morphometric Study of Dry Human Patella with Its Clinical Correlation Pratima Baisakh1, Lopamudra Nayak2, B Shanta Kumari2, Saurjya Ranjan Das3 1Associate Professor, 2Assistant Professor, Dept of Anatomy, 3Associate Professor, Dept of Anatomy, IMS & SUM Hospital, SOA (Deemed to be University), Bhubaneswar, Odisha, India Abstract Background- Patella is the largest sesamoid bone and forms the femuro-patellar component of the knee joint. Dimensions and classification of patellae are important anthropologically as well as clinically. Aims & Objectives- Morphometry of patella has a definite role in implant design and reconstructive surgeries of knee joint. The present study aims to find out different dimensions of patella and its facets on both sides and compared. Material & Methods- The morphometric study comprised of sixty (30 left and 30 right) dry human patella collected from department museum by using sliding digital calliper. The different parameters studied are height, width, thickness of patella, length and width of medial and lateral facets. Classification of patella was done by using the measurements of its articular facets. Observations- The mean height, width, thickness of patella of left side were found to be 37.79mm, 38.26mm, 19.35mm and that of right side were 35.72mm, 34.91mm, 17.64mm respectively. The mean width of medial and lateral articular facet of left side were 19.42mm, 21.21mm and that of right side were 18.33mm,20.97mm respectively. Width of lateral articular facet is significantly larger than that of medial articular facet of same side(p<0.05) and 85% of patella belongs to Wiberg typeB.The mean patellar thickness on left and right side is 19.35mm & 17.64mm respectively,left side being significantly more than(P<0.05) that of right side. Conclusion- These dimensions of patella may be helpful for different patellofemoral operations like knee arthroplasty, ligament repair, proximal tibial osteotomy, implant design for knee replacement and for forensic measurements. Key words- Patella, morphometry, facets, knee joint. Introduction because the position of tibial tuberosity vary in different individuals1-3.Superiorly placed, high-riding patella Patella is the largest sesamoid bone develop is called patella alta. An unusually small patella that in quadriceps femoris tendon. It forms the femuro- present above knee joint iscalled attenuated patella alta. patellar component of the knee joint. It is difficult when it is very low-riding in position it is called patella to specify the normal anatomical position of patella baja which can cause dysfunction during extension of knee joint4.It has a rough anterior surface, which has vertical ridges due to expansion of fibres from quadriceps Corresponding author: tendon. Its posterior surface is having large articular and Pratima Baisakh small nonarticular part. Articular part has two facets on Associate Professor, Department of anatomy IMS &SUM Hospital Siksha ‘O’ Anusandhan (Deemed either side of a median ridge. They articulate with the 5 to be University) Bhubaneswar, India corresponding facet on the patellar surface offemur . Phone - +91 9438844704 Each facet is divided by faint horizontal lines into equal Email- [email protected] thirds.A seventh ‘odd’ facet is presented by a narrow Indian Journal of Forensic Medicine & Toxicology, July-September 2021, Vol. 15, No. 3 431 strip along the medial border of the patella which comes departmental museum.The following parameters were in contact with the medial femoral condyle in extreme studied by using sliding digital calliper. flexion6. Lower non-articular part forms the apex of Patellar Height (PH)- Linear distance between patella &gives attachment to patellar ligament7. It is superior border and apex(Fig.1) involved in different postures like squatting,sitting andkneeling. Hence it is subjected to varied modification Patellar width (PW)- Linear distance between 8 depending on the ethnic and cultural variables .Patella medial and lateral border(Fig.2) gives protection to the knee joint anteriorly and increases the efficiency of quadriceps muscle during its extensor Patellar thickness (PT)- Linear distance between function acting as a fulcrum9.As it receives the insertion anterior surface and median ridge(Fig.3) of quadriceps femoris, its shape and size also affected Width of medial articular facet (WMAF)-Maximum by size and use of this muscle. Patella present as a shield distance between medial border and median ridge in anterior aspect of knee joint. Hence it is subjected to various type of trauma very often. Numerous pathologies Width of lateral articular facet (WLAF)-Maximum occur at patellofemoral unit leading to its degenerating distance between lateral border and median ridge changes. The various disordersthat affect patella are Statistical analysis- All statistical analysis was done osteoarthritis, fractures, chondromalacia patellae, by using statistical package for social science, window patellofemoral instability and idiopathic patellofemoral version 16 (SPSS-16 USA). Student t-test was used to pain syndrome. Knee arthroplasty and total knee find any significant difference exists between the right replacement is now a commonly performed procedure and left side patella. P<0.05 was taken as statistically to treat various knee problems. Outcome of knee significant. arthroplasty or patellofemoral arthroplasty is affected by 10 use of appropriate size and thickness of patella . Hence Result morphometry of patella has definite role in implant design and reconstructive surgeries occurring in the The mean values of different parameters of both sides knee joint. Wiberg classified patella into three groups were expressed in table1 &2. The mean height, width and basing on the position of median ridge, width of medial thickness of left side were 37.79mm(SD 4.11), 38.26mm and lateral articular facet11. Type A where Width of (SD 4.00) & 19.25mm(SD 1.91) (table1) and that of medial and lateral facet are same. Type B where Width right side were 35.72mm (SD 1.97),34.90mm(SD 2.11) of medial facet smaller than lateral facet and Type C and 17.54mm (0.73) respectively(table 2). Comparison where Width of medial facet much less than lateral facet. between different parameters of left and right side were Type B are common type ofpatella and it is the most reported in table 3. There is no significant difference stable variety. Any change in shape and size of patella in found in height and width of left and right-side patella. relation to tibial or femoral condylescan affects the knee Student’s test revealed thickness of left side patella is joint function.The present study carried out on different significantly more than that of right side(p<0.05). The morphometry of dry human patella of eastern Indian width of lateral articular facets were significantly larger origin, that have a great clinical importance for proper than the medial articular facet in both sides(P<0.05) functioning of knee joint and stability of patella. (table 3).According to Wiberg criteria, 85% patella belong to type B, 11.7% that of type A and 3.3% of type Materials & Methods C (table 4). The study was conducted on sixty dry human patella, 30 left & 30 right of unknown age & sex collected from 432 Indian Journal of Forensic Medicine & Toxicology, July-September 2021, Vol. 15, No. 3 Table 1; Measurements of left side patella Measurements Mean (mm) Standard deviation Maximum (mm) Minimum (mm) Patellar Height 37.79 4.11 43.75 33.49 Patellar width 38.26 4.00 45.42 33.91 19.25 Patellar thickness 1.91 22.67 16.50 Width of medial 19.42 2.61 23.20 15.21 articular facet Width of lateral 21.21 2.24 25.68 18.21 articular facet Table 2; Measurements of right side patella Measurements Mean (mm) Standard deviation Maximum (mm) Minimum (mm) Patellar Height 35.72 1.97 39.65 39.65 Patellar width 34.90 2.11 37.67 31.76 18.68 16.76 Patellar thickness 17.54 0.73 Width of medial 18.33 1.29 20.53 16.65 articular facet Width of lateral 20.97 1.27 22.77 19.26 articular facet Table 3;Comparison between Left &Right side patella Measurements Mean (mm) Mean (left) Mean (right) P value Patellar Height 36.75 37.79 35.72 0.22 38.26 Patellar width 36.58 34.90 0.15 Patellar thickness 18.39 19.35 17.64 0.03 Width of medial 18.33 18.87 19.42 0.96 articular facet Width of lateral 21.09 21.21 20.97 1.14 articular facet P value (WMAF/ 0.01 0.02 WLAF) Indian Journal of Forensic Medicine & Toxicology, July-September 2021, Vol. 15, No. 3 433 Table 4; Wiberg’s classification of Patella Type Number of patella % A 7 11.7 B 51 85 C 2 3.3 Figure 1; measurement of patellar Height Figure 2; Measurement of Patellar width 434 Indian Journal of Forensic Medicine & Toxicology, July-September 2021, Vol. 15, No. 3 Figure 3; Measurement of patellar thickness Discussion morphometry. The patellar height is an important factor for different knee surgery, cruciate ligament repair or Patella, the largest sesamoid bone present in anterior proximal tibial osteotomy to prepare knee implants18. aspect of kneeforming patello-femoral component of The thickness of left side patella is significantly higher knee joint. It gives attachment to quadriceps at its base than right side(p<0.05).That may be due to larger size and patellar ligament at the apex. It plays an important of quadriceps tendon in this side but it needs further role in extensor mechanism of knee joint acting as study. The width to thickness ratio is almost 2:1 which alever12. Its size and shape depend on the strain produced is represented in the graph 1.This finding coincides with by use of quadriceps13.