Our Providers


J. Thomas Grissom, M.D.

Dr. Grissom has extensive knowledge on how to treat chronic pain patients, with over 16 years of interventional pain management experience. He is board certified in anesthesia and pain management. Dr. Grissom received his medical doctorate from the University of Washington School of Medicine, received his residency training in anesthesiology from the University of Missouri-Columbia, with a pain management fellowship in Liverpool, NY. Dr. Grissom also has additional training which allows him to do various pain procedures that no other pain physician in Alaska can perform, thus providing increased level of service to his patients. In addition to serving as the medical director of The Algone Interventional Pain Clinic, he enjoys golfing, skiing and spending time with his three sons.


Matthew R. Peterson, M.D.

Dr. Peterson has extensive experience in treating acute & chronic pain patients. He received his undergraduate degree from the University of British Columbia, followed by his Medical Doctorate from the University of North Dakota. He completed his residency in Anesthesia as well as his fellowship in Intervention Pain Management with the University of Arizona. His special interest in pain medicine includes his dedication to providing relief to individuals with chronic and acute pain through a wide range of minimally invasive surgical and nonsurgical techniques.


Liam T. Walsh, M.D.

Dr. Walsh is passionate about helping patients with pain live a better quality of life.  A dedicated and caring physician, his training took place at some of the nation’s top institutions.  He earned his medical degree at Brooklyn College of Medicine, and completed both Anesthesiology residency and Interventional Pain Management fellowship at Dartmouth Medical Center.  He specializes in minimally invasive surgical techniques, radiofrequency ablation, as well as fluoroscopic- and ultrasound-guided injections.

Dr Walsh is also an accomplished free-skier, soccer player, and lover of the great outdoors.

Steven P. Johnson, M.D.

Dr. Steven Johnson is Board Certified in Family Practice in Canada, and in Anesthesia and Pain Management in the United States. Dr. Johnson grew up in Montreal, Canada where he attended McGill University, majoring in Engineering before continuing on to Medical School. He left Montreal to complete his Family Practice Residency at the University of Calgary where he was Board Certified in Family Practice. In 1979 he came to the United States for a residency in Anesthesia at the University of Vermont. Dr. Johnson continued his medical training with a Cardiac Anesthesia Fellowship at Emory University in Atlanta, Georgia.

Dr. Johnson practiced Anesthesia and Pain Medicine in Las Vegas, Nevada for 23 years. While there he became Board Certified in both Anesthesia and Pain Management. He also served as the Medical Director of the Sahara Surgery Center in Las Vegas. He was also the Chief of Anesthesia at the University Medical Center of Las Vegas.

Before coming to Alaska in 2008, Dr. Johnson spent four years in Kalispell, Montana where he was the Medical Director of the Northwest Spine and Pain Center.

Dr. Johnson specializes in a broad spectrum of pain management techniques: from patient consultations and medical management to the implantation of pain pumps and stimulators, epidurals and various types of nerve blocks. He also works with regenerative medicine which includes platelet rich plasma and stem cell therapy injections to naturally treat or heal conditions of the cartilage, tendons, and ligaments.

Dr. Johnson finds that Alaska is the perfect place for his extracurricular activities. He is an avid hockey player, who also enjoys skiing, golfing, fishing and hunting. Dr. Johnson is married and has two children in college.


Nichelle C. Renk, M.D.

As an interventional pain physician, Dr. Nichelle Renk believes the most successful treatment involves identifying the appropriate diagnosis and then implementing a combination of modalities truly tailored to her patient. This multidisciplinary approach to pain management includes the potential use of procedures, limited use of medications, physical therapy, braces and devices, pain psychology, complementary alternative medicine (e.g. acupuncture), and nutrition/lifestyle modification. With a precise diagnosis and multifaceted plan, Dr. Renk achieves dramatic long-lasting results for her patients.
Dr. Renk is passionate about getting to know and educating her patient. She goes over every diagnosis and each component of the plan in detail. Dr. Renk uses anatomical models and reviews the imaging with the patient to make sure the diagnosis is well understood. She provides a personalized handout at the end of the first visit listing the patient’s identified diagnoses and the plan for each multidisciplinary modality.
Dr. Renk performs advanced procedures head-to-toe but specializes in procedures of the cervical, thoracic, and lumbar spine, sacroiliac joint, and other nerves and joints of the body. Dr. Renk is one of few pain management physicians in Alaska to perform cooled radiofrequency procedures, a cutting-edge technology that creates a unique shaped and larger radiofrequency lesion to interrupt pain in the patient’s painful area of the body. Dr. Renk is planning on adding ultrasound-guided platelet rich plasma and stem cell injections to her practice in the near future.
Dr. Renk completed her medical doctorate at the Medical College of Virginia in Richmond, Virginia, anesthesiology residency at George Washington University Hospital in Washington DC, and interventional pain medicine fellowship at Stanford Hospital in Palo Alto, California. She is board-certified in anesthesiology and pain medicine by the American Board of Anesthesiology.
For the four years prior to joining Algone, Dr. Renk served in the United States Air Force as a Major and Chief/Director of the Joint Base Elmendorf-Richardson (JBER) Pain Management Clinic. She had a great experience taking care of her fellow airmen, troops, retirees, dependents, and VA beneficiaries. She won several awards in her tenure there and consistently achieved 99% or greater patient satisfaction.
Outside of work, Dr. Renk enjoys spending time with her family, hiking, and traveling.


Zach Kile, PA-C

Zach has lived in Alaska since 1999.  He had an Independent Surgical Assist practice in Anchorage assisting in multiple specialties including general, cardiovascular, neurology and orthopedic surgery.  He obtained his education at the University of Washington Medical School.  Zach is very excited about living and working in the Mat-Su Valley.  He brings a down-to-earth, common sense approach to medicine.  Zach operates Mat-Su Medical Locums, a locally owned business that provides medical coverage to local clinics when they are in need of providers.  In his spare time he enjoys fishing, running and hiking in the great Alaskan outdoors.  He is also a Mount Marathon finisher.


Cheryl K. Fitzgerald, PA-C

Cheryl is a certified Physician Assistant.  She has a BS degree in Health Studies from Western Michigan University and is a graduate of the Physician Assistant program at the University of Utah.  She has over 16 years of clinical experience working in various clinical settings including family practice, emergency/urgent care, preventative care, and orthopedic/fracture care.  Prior to obtaining her Physician Assistant degree, she worked for many years in radiologic technology.  Cheryl’s main focus is diagnosing and treating illness and injury in patients with chronic pain.  She believes in a multi-disciplinarian approach to pain management with the patient as the driving force.  She is skilled in treating with medication, injection therapy, and management of intrathecal pumps.


Stephen Shortridge, PA-C

Stephen was born in the Midwest but as an “Army brat” moved all over the United States and Europe.  Stephen came to Alaska in 1960, rode the Good Friday earthquake then left for a while.  He came back with his wife and first child in 1989 as a Registered Nurse and worked for 10 years in critical care and the ER.  He then went to Physician Assistant training at the University of Utah and graduated in 1996.  Since then he has practiced in family medicine, urgent care, internal medicine, and then interventional pain management.  He is passionate about family time with his wife and 2 children and boarding the big mountains of Alaska, especially on a Chugach Flyer snowboard, a local snowboarding brand of his own creation.  He also enjoys this great state’s beauty and bounty through mountain biking, photography, fishing and hunting.


Jesika Harrell, MMS, PA-C

Jesika Harrell is a Texas native who received her Master’s of Medical Science in Physician Assistant Studies from Methodist University in North Carolina. Prior to practicing at Algone, Jesika was a PA at a multi-disciplinary pain intervention clinic located on Elmendorf Air Force Base. Jesika is very passionate about practicing and researching regenerative medical interventions and anti-aging medicine. She is skilled at various in-office procedures to manage pain. Jesika enjoys gourmet cooking and considers herself a food connoisseur. In her spare time, she also takes pleasure in spending time with her husband, traveling, and woodworking.