**3. Newer innovation in preoperative planning**

Complex primary hip cases involving dysplasia at either side of the joint, trauma cases with fractures requiring arthroplasty, ankylosing spondylitis, protrusio cup and revision hip cases are a big challenge for arthroplasty surgeons. Rapid prototyping (RP) is a new concept adopted from industrial designing. This involves laying down series of additional layers of a material to regenerate a 3D model. Computer aided designing (CAD) program enables rapid production of a component with super accuracy [22]. This model is adopted in medical specialties including orthopedics to develop accurate replica of a body part in cross-section using CT scan as an input source. They are further printed using layered material to generate a 3D-printing model. This rapid prototype model provides a unique opportunity in preoperative planning, in terms of understanding deformity pattern, providing intraoperative referencing and surgical simulation. This further helps an arthroplasty surgeon for inventory planning as they can order necessary implants to make their availability on the day of surgery. This will save time during surgery and minimize on table bleeding, infection rate and thereby patient morbidity.

#### **3.1. Customized instruments and implants**

With advancement in the modern day technology, patient specific instruments can be obtained by using rapid prototyping [23]. This will aid in complex cases and will aid in improvement in operative results. In future more customized implants will be developed to use for the individual case demand that will fit for the purpose and will have better survival outcome for our patients by improving joint kinematics.

[2] Capello WN. Preoperative planning of total hip arthroplasty. Instructional Course Lectures.

Preoperative Planning of Total Hip Arthroplasty http://dx.doi.org/10.5772/intechopen.76368 17

[3] Harris WH. Traumatic arthritis of the hip after dislocation and acetabular fractures: Treatment by mold arthroplasty. An end-result study using a new method of result evaluation. The Journal of Bone and Joint Surgery. American Volume. 1969 Jun;**51**(4):737-755

[4] 36-Item Short Form Survey from the RAND Medical Outcomes Study. RANDHealth. Available from: http://www.rand.org/health/surveys\_tools/mos/mos\_core\_36item.html.

[5] Available from: https://www.hqip.org.uk/media/NJR%2014th%20Annual%20Report%20

[6] Available from: www.odep.org.uk/…/0/ODEPStatements/ODEP%20Benchmarks%20

[7] Noble PC, Alexander JW, Lindahl LJ, et al. The anatomic basis of femoral component

[8] Charnley J. Low friction arthroplasty of the hip. Vol. 246. Berlin: Springer Verlag; 1979

[9] Müller ME. Lessons of 30 years of total hip arthroplasty. Clinical Orthopaedics. 1992;

[10] Iorio R, Siegel J, Specht LM, et al. A comparison of acetate vs. digital templating for preoperative planning of total hip arthroplasty is digital templating accurate and safe? The

[11] Kearney R, Shaikh AH, O'Byrne JM. The accuracy and inter-observer reliability of acetate templating in total hip arthroplasty. Irish Journal of Medical Science. 2013 Sep;**182**(3):409-414

[12] Gamble P, Beer JD, Petruccelli D, et al. The accuracy of digital templating in uncemented

[13] Conn KS, Clarke MT, Hallett JP. A simple guide to determine the magnification of radiographs and to improve the accuracy of preoperative templating. Journal of Bone and

[14] Knight JL, Atwater RD. Preoperative planning for total hip arthroplasty. Quantitating its

[15] Della VAG, Comba F, Taveras N, et al. The utility and precision of analogue and digital preoperative planning for total hip arthroplasty. International Orthopaedics. 2008;**32**:

[16] Wimsey S, Pickard R, Shaw G.Accurate scaling of digital radiographs of the pelvis. A prospective trial of two methods. The Journal of Bone and Joint Surgery. 2006;**88**:1508-1512

[17] Bowerman JW, Sena JM, Chang R. The teardrop shadow of the pelvis; anatomy and

total hip arthroplasty. The Journal of Arthroplasty. 2010;**25**:529-532

utility and precision. The Journal of Arthroplasty. 1992;**7**:403-409

clinical significance. Radiology. 1982;**143**:659-662

1994;**43**:323-327

[Accessed Nov 5, 2014]

design. Clinical Orthopaedics. 1988;**235**:25-34

Journal of Arthroplasty. 2009;**24**:180

Joint Surgery. 2002;**84-B**:269-272

2017.pdf

**274**:12-21

289-294

2017\_rev.6.pdf

## **4. Conclusion**

Preoperative planning is an important step in the actual delivery of joint replacement as it allows the patient to go through a comprehensive assessment and preparation for undertaking joint replacement in a schematic fashion. This begins with a thorough clinical assessment by their operating surgeon and a series of investigations followed by actual planning of their hip joint replacement, utilizing template on their standardized radiographs. Templating process allows assessment of their anatomical landmarks to mark as reference points while implanting prosthesis with correct depth. This will allow the surgeons to restore hip biomechanics and thereby improving post-surgical outcomes. This will further allow anticipating difficulties and pitfalls prior to surgery.

Some surgeons do not like to proceed with this important step of templating prior to their joint replacement surgeries. However, unless it is done systematically, it might be difficult, even for the experience hip surgeons to identify those hips, which will definitely benefit from a proper anatomical and mechanical assessment. Moreover, these less planed cases without templating are at increase risk to suffer inadequate hip biomechanics and higher complication rates including trendelenburg gait, joint dislocation, significant leg length discrepancy, peri prosthetic fracture and trochanteric pain. It has been proven to have similar efficacy of preoperative templating by the junior surgeons in training as their senior counter parts [11]. Thus it makes it a legitimate cause for carrying out this vital process of templating of the hip joint prior to actual implantation of the prosthesis. In crux this will improve the long-term outcome and patient satisfaction in both subjective and objective manner [3, 4].
